19-5488; Rev 0; 8/10 PMBus 5通道电源管理器 和智能风扇控制器 MAX34441是一款复杂系统监测器，可管理多达 5 路电源 和一个风扇。电源管理器监测电源输出电压并连续检查用户 可编程过压、欠压门限。它还能够调整电源输出电压的裕量， 使其达到用户要求的水平。采用闭环结构调节裕量，器件据 此自动调整脉宽调制(PWM) 输出，然后测量所产生的输出 电压。电源管理器还能够在上电及断电时按任意顺序对电源 排序。利用外部电流检测放大器，器件还能够监测电流。 器件还具有闭环风扇速度控制功能。用户可根据特定的温度 断点设置风扇控制 PWM占空比或 RPM 转速，器件基于这 些设置自动调整风扇速度，并通过特殊方式降低可闻噪声 和功耗。 应用 特性 ♦♦5通道电源管理 电压测量 /监测 12位、1% 精度的差分ADC 最小 /最大门限偏移检测 配合外部电流检测放大器支持电流监测 闭环裕量自动调节 可编程上电和断电顺序 电源就绪输出 ♦♦1通道风扇控制 支持 3 线和 4 线风扇 闭环风扇转速自动控制 支持双转速计风扇 风扇故障检测 智能电网系统 ♦♦支持多达6 个温度传感器 外部测温二极管接口，带有自动串联电阻抵消功能 1个内部温度传感器 支持多达4片I2C外部数字温度传感器IC 对所有温度传感器进行故障检测 工业控制 ♦♦PMBus™兼容命令接口 网络交换机 / 路由器 基站 服务器 ♦♦I2C/SMBus™兼容串行总线，带有总线超时检测功能 ♦♦板载非易失故障记录和默认配置设置 ♦♦无需外部时钟 ♦♦+3.3V供电电压 定购信息 TEMP RANGE PIN-PACKAGE MAX34441ETL+ PART -40NC to +85NC 40 TQFN-EP* MAX34441ETL+T -40NC to +85NC 40 TQFN-EP* +表示无铅(Pb)/ 符合 RoHS 标准的封装。 T= 卷带包装。 *EP= 裸焊盘。 PMBus 是SMIF,Inc. 的商标。 SMBus 是IntelCorp. 的商标。 注意：该器件某些版本的规格可能与发布的规格不同，会以勘误表的形式给出。通过不同销售渠道可能同时获得器件的多个版本。欲了解器件勘误 表信息，请点击：china.maxim-ic.com/errata。 ________________________________________________________________ Maxim Integrated Products 1 本文是英文数据资料的译文，文中可能存在翻译上的不准确或错误。如需进一步确认，请在您的设计中参考英文资料。 有关价格、供货及订购信息，请联络Maxim亚洲销售中心：10800 852 1249 (北中国区)，10800 152 1249 (南中国区)， 或访问Maxim的中文网站：china.maxim-ic.com。 MAX34441 概述 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 目录 AbsoluteMaximumRatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 RecommendedOperatingConditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 DCElectricalCharacteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 I2C/SMBusInterfaceElectricalSpecifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 I2C/SMBus 时序 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 典型工作特性 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 引脚配置 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 引脚说明 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 方框图 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 多器件连接框图 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 详细说明 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 地址选择. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 SMBus/PMBus 操作 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 SMBus/PMBus 通信示例 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 群发命令 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 群发命令写格式 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 寻址 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 ALERT 和报警响应地址(ARA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 报警响应地址 (ARA)字节格式 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 主器件发送或读取的位数太少. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 主器件发送或读取的字节数太少 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 主器件发送的字节或位数太多 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 主器件读取的字节或位数太多 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 主器件在从地址字节中设置的读取状态位错误. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 接收到不支持的命令代码 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 接收到无效数据 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 主器件从只写命令请求读操作 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 主器件向只读命令请求写操作 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 SMBus超时 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 PMBus 操作 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 PMBus 协议支持. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 数据格式 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 解析接收到的 DIRECT格式数据 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 发送 DIRECT格式数据 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 故障管理和报告. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 系统看门狗定时器 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 温度传感器操作 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 2 PMBus 5通道电源管理器 和智能风扇控制器 风扇控制操作 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 自动风扇控制操作. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 脉冲展宽 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 风扇上旋. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 PMBus 命令. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 PAGE(00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 OPERATION(01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 ON_OFF_CONFIG(02h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 CLEAR_FAULTS(03h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 WRITE_PROTECT(10h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 STORE_DEFAULT_ALL(11h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 RESTORE_DEFAULT_ALL(12h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 CAPABILITY(19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 VOUT_MODE(20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 VOUT_MARGIN_HIGH(25h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 VOUT_MARGIN_LOW(26h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 VOUT_SCALE_MONITOR(2Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 IOUT_CAL_GAIN(38h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 FAN_CONFIG_1_2(3Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 FAN_COMMAND_1(3Bh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 VOUT_OV_FAULT_LIMIT(40h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 VOUT_OV_WARN_LIMIT(42h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 VOUT_UV_WARN_LIMIT(43h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 VOUT_UV_FAULT_LIMIT(44h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 IOUT_OC_WARN_LIMIT(46h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 IOUT_OC_FAULT_LIMIT(4Ah)................................................. 33 OT_FAULT_LIMIT(4Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 OT_WARN_LIMIT(51h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 POWER_GOOD_ON(5Eh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 POWER_GOOD_OFF(5Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 TON_DELAY(60h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 TON_MAX_FAULT_LIMIT(62h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 TOFF_DELAY(64h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 STATUS_BYTE(78h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 STATUS_WORD(79h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 STATUS_VOUT(7Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 STATUS_CML(7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 双风扇应用. 3 MAX34441 目录 ( 续 ) MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 目录 ( 续 ) STATUS_MFR_SPECIFIC(80h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 STATUS_FANS_1_2(81h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 READ_VOUT(8Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 READ_IOUT(8Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 READ_TEMPERATURE_1(8Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 READ_FAN_SPEED_1(90h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 PMBUS_REVISION(98h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 MFR_ID(99h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 MFR_MODEL(9Ah). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 MFR_REVISION(9Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 MFR_LOCATION(9Ch). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 MFR_DATE(9Dh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 MFR_SERIAL(9Eh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 MFR_MODE(D1h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 MFR_VOUT_PEAK(D4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 MFR_IOUT_PEAK(D5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 MFR_TEMPERATURE_PEAK(D6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 MFR_VOUT_MIN(D7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 MFR_FAULT_RESPONSE(D9h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 MFR_FAULT_RETRY(DAh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 MFR_NV_FAULT_LOG(DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 MFR_TIME_COUNT(DDh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44 MFR_MARGIN_CONFIG(E0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44 MFR_TEMP_SENSOR_CONFIG(F0h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 MFR_FAN_CONFIG(F1h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 MFR_FAN_LUT(F2h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 TEMPERATURESTEP：温度值设置 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 FANSPEEDSTEP：风扇 PWM占空比或风扇转速设置. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 MFR_READ_FAN_PWM(F3h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 MFR_FAN_FAULT_LIMIT(F5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 MFR_FAN_WARN_LIMIT(F6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 应用信息 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 电源去耦 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 开漏引脚 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 典型工作电路 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 封装信息 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 修订历史 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4 PMBus 5通道电源管理器 和智能风扇控制器 图1. 自动风扇控制. . . . . . . 图2. 风扇速度示例 . . . . . . . 图3. 风扇上旋. . . . . . . . . . 图 4. 电源排序 . . . . . . . . . . 图 5.MFR_NV_FAULT_LOG . 图 6. 风扇查找表(LUT) 格式 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 24 25 34 42 49 表目录 表1.PMBus 命令代码 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 表 2.PMBus/SMBus串口地址 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 表3.PMBus 命令代码系数 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 表4.DIRECT格式数据的系数. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 表5. 器件参数监测状态 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 表 6.DS75LV地址引脚配置 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 表7. 风扇控制工作模式 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 表 8. 页命令 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 表9.OPERATION 命令字节(ON_OFF_CONFIG 的第 3 位=1时) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 表10.OPERATION 命令字节(ON_OFF_CONFIG 的第 3 位=0 时). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 表11.ON_OFF_CONFIG(02h) 命令字节 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 表12.WRITE_PROTECT命令字节. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 表13.CAPABILITY命令字节 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 表14.VOUT_SCALE_MONITOR................................................. 30 表15.FAN_CONFIG_1_2 命令字节 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 表16.PWM 风扇模式 (FAN_CONFIG_1_2 的第 6 位=0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 表17.RPM 风扇模式 (FAN_CONFIG_1_2 的第 6 位=1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 表18.IOUT_OC_FAULT_LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 表19.TON_MAX_FAULT_LIMIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 表 20.STATUS_BYTE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 表 21.STATUS_WORD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 表 22.STATUS_VOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 表 23.STATUS_CML. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 表 24.STATUS_MFR_SPECIFIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 表 25.STATUS_FANS_1_2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 表 26.MFR_MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 表 27.MFR_FAULT_RESPONSE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 表 28.MFR_FAULT_RESPONSE 编码. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 表 29.MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 表30.MFR_MARGIN_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 表31.MFR_TEMP_SENSOR_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 表32.MFR_FAN_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 表33.MFR_FAN_LUT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 表34. 有效温度范围 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 表35. 监测风扇故障和报警参数. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 5 MAX34441 图目录 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 Absolute Maximum Ratings Operating Temperature Range........................... -40NC to +85NC Storage Temperature Range............................. -55NC to +125NC Lead Temperature (soldering, 10s).................................+260NC Soldering Temperature (reflow).......................................+260NC VDD to VSS............................................................-0.3V to +5.5V RS- to VSS.............................................................-0.3V to +0.3V All Other Pins Except REG18 and REG25 Relative to VSS......................... -0.3V to (VDD + 0.3V)* Continuous Power Dissipation (TA = +70NC) 40-Pin TQFN (derate 35.7mW/NC above +70NC)..........................2857.1mW *Subject to not exceeding +5.5V. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Recommended Operating Conditions (TA = -40NC to +85NC.) PARAMETER SYMBOL MAX UNITS 2.7 5.5 V VIH 0.7 x VDD VDD + 0.3 V VIL -0.3 0.3 x VDD V VDD Operating Voltage Range VDD Input Logic 1 Input Logic 0 CONDITIONS (Note 1) MIN TYP Input Logic-High: SCL, SDA, MSCL, MSDA VI2C_IH 2.7V P VDD P 3.6V (Note 1) 2.1 VDD + 0.3 V Input Logic-Low: SCL, SDA, MSCL, MSDA VI2C_IL 2.7V P VDD P 3.6V (Note 1) -0.3 +0.8 V DC Electrical Characteristics (VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.) PARAMETER Supply Current SYMBOL ICPU CONDITIONS Brownout Hysteresis VBOH Monitors VDD (Note 1) Internal System Clock fMOSC Output Logic-Low Output Logic-High PWM, PSEN Pullup Current fERR:MOSC VOL1 VOH1 IPU 2.40 ADC Internal Reference Temperature Drift 6 2.46 2.55 30 mV MHz -3 +2 -6.5 +1.6 VPIN = VSS, VDD = 3.3V 0.4 VDD 0.5 38 % V V 55 107 FA -1 +1 % -0.5 +0.5 % 1.225 VERR V 4.0 -40NC P TA P +25NC IOL = 4mA (Note 1) IOH = -2mA (Note 1) UNITS mA +25NC P TA P +85NC ADC Internal Reference ADC Voltage Measurement Error MAX 8 Monitors VDD (Note 1) System Clock Error (Note 3) TYP 2.5 IPROGRAM VBO Brownout Voltage MIN (Note 2) V PMBus 5通道电源管理器 和智能风扇控制器 (VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS ADC Internal Reference Initial Accuracy (+25NC) ADC Full-Scale Input Voltage VFS VLSB 1.213 1.225 MAX UNITS +1 mV 1.237 300 ADC Bit Resolution RS+ Input Resistance RIN INL Bits 15 MI Q4 DNL Q1 VOFFSET Internal Temperature Measurement Error Remote Temperature Measurement Error (MAX34441 Error Only) LSB LSB LSB Q2 -3 +3 TA = 0NC to +60NC, TDIODE = +60NC to +120NC -1.5 +1.5 TA = 0NC to +60NC, TDIODE = -45NC to +120NC -1.75 +1.75 TA = -40NC to +85NC, TDIODE = +60NC to +120NC -2.75 +2.75 TA = -40NC to +85NC, TDIODE = -45NC to +120NC -3.0 +3.0 TA = -40NC to +85NC V FV 12 ADC Integral Nonlinearity ADC Offset TYP -1 ADC Measurement Resolution ADC Differential Nonlinearity MIN NC NC Store Default All Time 37 ms Nonvolatile Log Write Time 12 ms Nonvolatile Log Delete Time 200 ms Flash Endurance Data Retention NFLASH TA = +50NC 20,000 TA = +50NC 100 Voltage Sample Rate Write Cycles Years 5 ms Current Sample Rate 200 ms RPM Sample Rate 1000 ms Temperature Sample Rate 1000 ms 12 ms Device Startup Time PWM Frequency PWM Resolution Measured from POR until monitoring begins Power supply Fan 62.5 30 kHz 25,000 Power supply 6 Fan 7 Hz Bits 7 MAX34441 DC Electrical characteristics (continued) MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 I2C/SMBus Interface Electrical Specifications (VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 100 kHz SCL Clock Frequency fSCL 10 Bus Free Time Between STOP and START Conditions tBUF 4.7 Fs Hold Time (Repeated) START Condition tHD:STA 4.0 Fs Low Period of SCL tLOW 4.7 Fs High Period of SCL tHIGH 4.0 Fs Receive 0 Transmit 300 Data Hold Time tHD:DAT Data Setup Time tSU:DAT 100 START Setup Time tSU:STA 4.7 SDA and SCL Rise Time ns ns Fs 300 tR SDA and SCL Fall Time 300 tF STOP Setup Time Clock Low Timeout tSU:STO 4.0 tTO 25 ns ns Fs 35 ms Note 1: All voltages are referenced to ground (VSS). Currents entering the IC are specified as positive, and currents exiting the IC are negative. Note 2: This does not include pin input/output currents. Note 3: Guaranteed by design. I2C/SMBus时序 SDA tBUF tF tLOW tHD:STA tSP SCL tHD:STA tHIGH tR tHD:DAT STOP START NOTE: TIMING IS REFERENCED TO VIL(MAX) AND VIH(MIN). 8 tSU:STA tSU:DAT REPEATED START tSU:STO PMBus 5通道电源管理器 和智能风扇控制器 (TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. SUPPLY VOLTAGE SUPPLY CURRENT vs. TEMPERATURE 2.6 2.6 2.5 2.4 IDD (mA) 2.5 IDD (mA) MAX34441 toc02 2.7 MAX34441 toc01 2.7 VDD = 3.3V 2.3 2.4 TA = +25°C 2.3 2.2 2.2 2.1 2.1 2.0 2.0 -40 -20 0 20 40 60 80 2.7 100 3.1 3.5 3.9 4.3 4.7 5.1 5.5 TEMPERATURE (°C) VDD (V) WEAK PULLUP VOLTAGE vs. TIME AT POR (UNLOADED PINS, VDD = 3.3V) IDD vs. TIME DURING A FLASH WRITE (TA = +25°C, VDD = 3.3V) MAX34441 toc04 MAX34441 toc03 C1 = PSEN0 0V C3 = PWM0 0V 1mA/div 1V/div C2 = VDD 0V 0A 2ms/div 1ms/div FILTERED MARGINING VOLTAGE vs. TIME DURING MARGIN UP MAX34441 toc05 200mV/div 0V 100ms/div 9 MAX34441 典型工作特性 引脚配置 VSS REG18 PSEN3 PWM2 PWM1 PSEN2 PSEN1 PWM0 TOP VIEW REG25 PSEN0 30 29 28 27 26 25 24 23 22 21 SDA 31 20 PWM3 SCL 32 19 PSEN4 A0/MUXSEL 33 18 PWM4 FAULT 34 17 TACH5 CONTROL 35 16 PWM5 MAX34441 VSS 36 15 MSCL A1/PG/TACHSEL 37 14 MSDA ALERT 38 RS-5 39 13 RST EP + 12 RS-2 11 RS+2 7 8 9 10 VDD RS-1 6 RS-0 5 RS+1 RS+4 4 RS+0 3 RS-3 2 RS+3 1 VSS RS+5 40 RS-4 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 TQFN (6mm × 6mm × 0.75mm) 引脚说明 10 引脚 名称 功能 11 RS+2 12 RS-2 ADC4电压测量的地参考端。 数字电源回路节点(地)。 电源 ADC电压检测输入，相对于 RS-4测量。 ADC3电压测量的地参考端。 电源 ADC电压检测输入，相对于 RS-3 测量。 电源 ADC电压检测输入，相对于 RS-0 测量。 ADC0电压测量的地参考端。 电源 ADC电压检测输入，相对于 RS-1测量。 电源电压，利用一个 0.1µF电容将VDD 旁路至 VSS。 ADC1电压测量的地参考端。 电源 ADC电压检测输入，相对于 RS-2 测量。 ADC2电压测量的地参考端。 13 RST 低电平有效复位输入。 14 MSDA 主控制器I2C 数据输入 / 输出，开漏输出。 15 MSCL 主控制器I2C 时钟输出，开漏输出。 16 PWM5 风扇 PWM 输出 #5，CMOS 推挽式输出。风扇被禁用时为低电平，占空比为100% 时，该引脚连续保持高 电平。 17 TACH5 风扇转速计输入。 18 PWM4 19 PSEN4 PWM 裕量调节输出#4。裕量调节被禁用时为高阻，占空比为100% 时，该引脚连续保持高电平。 电源使能输出#4。通过 MFR_MODE 可设置为高电平有效或低电平有效，以及开漏或 CMOS 推挽输出。 1 RS-4 2, 21, 36 VSS 3 RS+4 4 RS-3 5 RS+3 6 RS+0 7 RS-0 8 RS+1 9 VDD 10 RS-1 PMBus 5通道电源管理器 和智能风扇控制器 引脚 名称 功能 20 PWM3 22 REG18 23 PSEN3 PWM 裕量调节输出#3。裕量调节被禁用时为高阻，占空比为100% 时，该引脚连续保持高电平。 低电压数字电路稳压器，用1μF 和10nF电容将 REG18 旁路至 VSS。请勿将其它电路连接至该引脚。 电源使能输出#3。通过 MFR_MODE 可设置为高电平有效或低电平有效，以及开漏或 CMOS 推挽输出。 PWM 裕量调节输出#2。裕量调节被禁用时为高阻，占空比为100% 时，该引脚连续保持高电平。 电源使能输出#2。通过 MFR_MODE 可设置为高电平有效或低电平有效，以及开漏或 CMOS 推挽输出。 PWM 裕量调节输出#1。裕量调节被禁用时为高阻，占空比为100% 时，该引脚连续保持高电平。 电源使能输出#1。通过 MFR_MODE 可设置为高电平有效或低电平有效，以及开漏或 CMOS 推挽输出。 PWM 裕量调节输出#0。裕量调节被禁用时为高阻，占空比为100% 时，该引脚连续保持高电平。 模拟电路稳压器，用1μF 和10nF电容将 REG25 旁路至 VSS。请勿将其它电路连接至该引脚。 电源使能输出#0。通过 MFR_MODE 可设置为高电平有效或低电平有效，以及开漏或 CMOS 推挽输出。 I2C/SMBus 兼容输入 / 输出。 I2C/SMBus 兼容时钟输入。 SMBus 地址 0 输入 /多路复用器控制输出。器件上电时通过该双功能引脚确定SMBus 地址；将一个100kΩ电 阻从该引脚连接至 VSS 或 VDD，设置地址。器件上电后，该引脚变为输出，作为外部模拟复用器的电压 /电 流选择器。MUXSEL为低电平时用于电压测量，为高电平时用于电流测量。 低电平有效故障指示开漏输入 / 输出。全局中的一路或多路电源由于故障条件而关断时，将触发该引脚产 24 PWM2 25 PSEN2 26 PWM1 27 PSEN1 28 PWM0 29 REG25 30 PSEN0 31 SDA 32 SCL 33 A0/MUXSEL 34 FAULT 35 CONTROL 器件使能。通过 ON_OFF_CONFIG 选择低电平有效或高电平有效电源控制。该引脚带有一个 50 μs 尖峰脉冲 抑制滤波器。 37 A1/PG/ TACHSEL SMBus 地址1输入 /电源就绪输出。器件上电时通过该双功能引脚确定SMBus 地址；将一个100kΩ电阻从该 引脚连接至 VSS 或 VDD，设置地址。器件上电后，该引脚变为输出，当所有使能电源高于其对应的 POWER_ GOOD_ON 门限时，该引脚跳变到高电平。或者，在双风扇应用中，亦可通过 MFR_MODE 将该引脚配置为 在两个转速计之间进行选择。 38 ALERT 生报警指示。此外，通过监测该引脚，当其触发产生报警输出时，关闭所有电源。该引脚用于为多个器件 的电源组提供全局硬件控制。触发RST 或关闭器件后重新上电时，该引脚输出将无条件解除报警状态。该 引脚带有一个 50 μs 尖峰脉冲抑制滤波器。 低电平有效、开漏报警输出。 39 RS-5 温度检测二极管的 ADC电压输入，负检测端，相对于 RS+5测量。 40 RS+5 温度检测二极管的 ADC电压输入，正检测端，相对于 RS-5测量。 裸焊盘( 封装底层)，将 EP 连接至 VSS。 注：除VDD、VSS、REG18、REG25、ADC 和 EP 之外，全部引脚在器件上电和复位期间均为高阻，具有 50 μA 上拉。器件复位后，去掉弱上拉， 引脚配置为输入或输出。 — EP 11 MAX34441 引脚说明(续) 方框图 VDD VSS REG25 VSS REG18 VSS POWER CONTROL PULSEWIDTH MODULATOR 2.5V VREG 1.8V VREG PWM0 PWM1 PWM2 PWM3 PWM4 PWM5 PSEN0 4MHz OSCILLATOR MSDA MSCL SDA SCL RST ALERT FAULT CONTROL A0/MUXSEL A1/PG/TACHSEL SMBus MASTER INTERFACE ADC SYSTEM CONTROL SIGNALS RAM FLASH PSEN1 PSEN2 PSEN3 PSEN4 FAN TACHOMETER INPUT SMBus SLAVE INTERFACE MAX34441 12 16-BIT MAXQ RISC CORE POWERSUPPLY OUTPUT ENABLES MUX MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 TEMP SENSOR TACH5 RS+0 RS-0 RS+1 RS-1 RS+2 RS-2 RS+3 RS-3 RS+4 RS-4 RS+5 RS-5 PMBus 5通道电源管理器 和智能风扇控制器 +3.3V ALERT HOST INTERFACE CLOCK DATA CONTROL RST SDA SCL RST ALERT MAX34441 #0 FAULT CONTROL A1/PG/TACHSEL A0/MUXSEL +3.3V SDA SCL RST ALERT FAULT MAX34441 #1 CONTROL A1/PG/TACHSEL A0/MUXSEL ADDITIONAL DEVICES 13 MAX34441 多器件连接框图 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 详细说明 MAX34441是一款高度集成的系统监测器，基于 4MHz、 16 位、MAXQ® 微控制器，带有工厂可编程功能，可监测多 达 5 路电源和一个系统冷却风扇。器件具有电源闭环控制、 风扇转速监测和本地 / 远端温度检测功能。 电源管理器监测电源输出电压，不断检查用户可编程的过压 和欠压门限。它还能将电源输出电压的裕量调节至用户设置 的水平。采用闭环结构调节裕量，器件由此自动调节脉宽调 制 (PWM) 输出，然后测量产生的输出电压。电源管理器还 能够在上电及断电时按任意顺序对电源排序。使用外部电流 检测放大器时，器件还能监测电流。 二极管。可以为每个传感器分别增加温度偏移，以补偿系统 温差。通过专用的 I2 C/SMBus 接口与 DS75LV 温度传感器 通信。 器件还具有闭环风扇速度控制功能。用户可根据特定的温度 断点设置风扇控制 PWM占空比或风扇 RPM 转速，器件基 于这些设置自动调整风扇速度，并通过特殊方式降低可闻 噪声和功耗。 器件提供 ALERT 和 FAULT 输出信号，主器件通过 PMBus 兼 容通信端口进行通信。提供地址输入连接，允许系统I/O总 线上挂接 4片 MAX34441器件。 温度监测功能可支持多达 6 个温度传感器的检测，包括片上 温度传感器、4 个 DS75LV 数字温度计和一个远端温度检测 表1. PMBus命令代码 CODE 00h 01h 02h 03h 10h 11h 12h 19h 20h 25h 26h 2Ah 38h 3Ah 3Bh 40h 42h 43h 44h 46h 4Ah 4Fh COMMAND NAME PAGE OPERATION ON_OFF_CONFIG CLEAR_FAULTS WRITE_PROTECT STORE_DEFAULT_ALL RESTORE_DEFAULT_ALL CAPABILITY VOUT_MODE VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_SCALE_MONITOR IOUT_CAL_GAIN FAN_CONFIG_1_2 FAN_COMMAND_1 VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT IOUT_OC_WARN_LIMIT IOUT_OC_FAULT_LIMIT OT_FAULT_LIMIT TYPE PAGE 0–4 R/W Byte R/W Byte R/W Byte Send Byte R/W Byte Send Byte Send Byte Read Byte Read Byte R/W Word R/W Word R/W Word R/W Word R/W Byte R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W R/W R/W W R/W W W R R R/W R/W R/W R/W — — R/W R/W R/W R/W R/W R/W — MAXQ 是 MaximIntegratedProducts,Inc. 的注册商标。 14 PAGE 5 PAGE 6–11 (NOTE R/W — R/W W R/W W W R R — — — — R/W R/W — — — — — — — 1) R/W — R/W W R/W W W R R — — — — — — — — — — — — R/W PAGE 255 R/W W R/W W R/W W W R R — — — — — — — — — — — — — NO. OF BYTES FLASH STORED (NOTE 2) DEFAULT VALUE (NOTE 2) 1 1 1 0 1 0 0 1 1 2 2 2 2 1 2 2 2 2 2 2 2 2 N N Y N N N N N FIXED Y Y Y Y Y Y Y Y Y Y Y Y Y 00h 00h 1Ah — 00h — — 00h/10h 40h 0000h 0000h 7FFFh 0000h 00h FFFFh 7FFFh 7FFFh 0000h 0000h 7FFFh 0000h 7FFFh PMBus 5通道电源管理器 和智能风扇控制器 CODE COMMAND NAME TYPE PAGE 0–4 51h 5Eh 5Fh 60h 62h 64h 78h 79h 7Ah 7Eh 80h 81h 8Bh 8Ch 8Dh 90h 98h 99h 9Ah 9Bh 9Ch 9Dh 9Eh D1h D4h D5h D6h D7h D9h DAh DCh DDh E0h F0h F1h F2h F3h F5h F6h OT_WARN_LIMIT POWER_GOOD_ON POWER_GOOD_OFF TON_DELAY TON_MAX_FAULT_LIMIT TOFF_DELAY STATUS_BYTE STATUS_WORD STATUS_VOUT STATUS_CML STATUS_MFR_SPECIFIC STATUS_FANS_1_2 READ_VOUT READ_IOUT READ_TEMPERATURE_1 READ_FAN_SPEED_1 PMBUS_REVISION MFR_ID MFR_MODEL MFR_REVISION MFR_LOCATION MFR_DATE MFR_SERIAL MFR_MODE MFR_VOUT_PEAK MFR_IOUT_PEAK MFR_TEMPERATURE_PEAK MFR_VOUT_MIN MFR_FAULT_RESPONSE MFR_FAULT_RETRY MFR_NV_FAULT_LOG MFR_TIME_COUNT MFR_MARGIN_CONFIG MFR_TEMP_SENSOR_CONFIG MFR_FAN_CONFIG MFR_FAN_LUT MFR_READ_FAN_PWM MFR_FAN_FAULT_LIMIT MFR_FAN_WARN_LIMIT R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word Read Byte Read Word Read Byte Read Byte Read Byte Read Byte Read Word Read Word Read Word Read Word Read Byte Read Byte Read Byte Read Word Block R/W Block R/W Block R/W R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word Block Read Block Read R/W Word R/W Word R/W Word Block R/W Read Word R/W Word R/W Word — R/W R/W R/W R/W R/W R R R R R — R R — — R R R R R/W R/W R/W R/W R/W R/W — R/W R/W R/W R R R/W — — — — — — PAGE 5 PAGE 6–11 (NOTE — — — — — — R R — R — R — — — R R R R R R/W R/W R/W R/W — — — — — R/W R R — — R/W R/W R R/W R/W 1) R/W — — — — — R R — R R — — — R — R R R R R/W R/W R/W R/W — — R/W — — R/W R R — R/W — — — — — PAGE 255 — — — — — — R R — R — — — — — — R R R R R/W R/W R/W R/W — — — — — R/W R R — — — — — — — NO. OF BYTES FLASH STORED (NOTE 2) DEFAULT VALUE (NOTE 2) 2 2 2 2 2 2 1 2 1 1 1 1 2 2 2 2 1 1 1 2 8 8 8 2 2 2 2 2 2 2 255 4 2 2 2 32 2 2 2 Y Y Y Y Y Y N N N N N N N N N N FIXED FIXED FIXED FIXED Y Y Y Y N N N N Y Y Y N Y Y Y Y N Y Y 7FFFh 0000h 0000h 0000h 0000h 0000h 00h 0000h 00h 00h 00h 00h 0000h 0000h 0000h 0000h 11h 4Dh 52h 3030h (Note 3) (Note 3) (Note 3) 0000h 0000h 0000h 8000h 7FFFh 0000h 0000h (Note 4) (Note 5) 0000h 0000h 0000h (Note 6) 0000h 0000h 0000h 注 1：标有阴影的命令为通用命令，从任何页面访问时都产生相同的器件响应。 注 2：在 Flash Stored 栏中， “N”表示执行 STORE_DEFAULT_ALL命令时该参数不存储在闪存中，上电复位或触发 RST 引脚时自动加载 Default Value 栏的数值。Flash Stored 栏中的“Y”表示执行 STORE_DEFAULT_ALL命令时该参数的当前加载值存储在闪存中，并在上电复位或触 发 RST 引脚时自动加载，Default Value 栏中的数值为出厂时的数值。Flash Stored 栏中的“FIXED”表示该值在工厂固定，不能修改。 15 MAX34441 表1. PMBus命令代码(续) MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 表1. PMBus命令代码(续) 注 3：该 8 字节数据块的工厂设置默认值为3130313031303130h。 注 4：MFR_NV_FAULT_LOG 完整数据块的工厂设置默认值为 FFh。 注 5：该 4 字节数据块的上电复位值为 00000000h。 注 6：MFR_FAN_LUT完整数据块的工厂设置默认值为 00h。 表 2. PMBus/SMBus串口地址 A0 7-BIT SLAVE ADDRESS 100kI to VSS 1101 010 (D4h) 100kI to VDD 1101 011 (D6h) A1 100kI to VSS 100kI to VDD 地址选择 器件上电时，通过 A0 和 A1引脚确定 PMBus/SMBus 串口 地址。 100kI to VSS 1101 100 (D8h) 100kI to VDD 1101 101 (DAh) SMBus/PMBus 操作 器件采用 SMBus 格式实现 PMBus 命令结构。主器件和从器 件之间的数据流结构如下所示，有几种不同的会话类型。所 有会话均以主器件发送 7位从器件地址 (R/W=0)，然后紧 跟一个命令代码开始。数据传输为最高有效位(MSB) 在前。 SMBus/PMBus 通信示例 READ WORD FORMAT 1 7 S SLAVE ADDRESS 1 W 1 8 A COMMAND CODE 1 1 7 A Sr SLAVE ADDRESS 1 1 8 1 8 1 1 R A DATA BYTE LOW A DATA BYTE HIGH NA P READ BYTE FORMAT 1 7 1 1 8 1 1 7 1 1 8 1 1 S SLAVE ADDRESS W A COMMAND CODE A Sr SLAVE ADDRESS R A DATA BYTE NA P 1 8 1 8 A COMMAND CODE A DATA BYTE LOW WRITE WORD FORMAT 1 7 S SLAVE ADDRESS 1 W 1 8 1 1 A DATA BYTE HIGH A P WRITE BYTE FORMAT 1 7 S SLAVE ADDRESS 1 W 1 8 1 8 1 1 A COMMAND CODE A DATA BYTE A P SEND BYTE FORMAT 16 1 7 1 1 8 1 1 S SLAVE ADDRESS W A COMMAND CODE A P KEY: S = START Sr = REPEATED START P = STOP W = WRITE BIT (0) R = READ BIT (1) A = ACKNOWLEDGE (0) NA = NOT ACKNOWLEDGE (1) SHADED BLOCK = SLAVE TRANSACTION PMBus 5通道电源管理器 和智能风扇控制器 器件支持群发命令。利用群发命令，主器件能够通过一个较 长的连续数据流对同一串行总线上的多个器件写入不同数 据。所有被寻址的器件在会话期间等待主器件发出 STOP 命 令，然后开始响应命令。 群发命令写格式 SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE 1 1 7 1 1 8 1 8 1 8 1 S SLAVE ADDRESS W A COMMAND CODE A DATA BYTE LOW A DATA BYTE HIGH A UUU SLAVE ADDRESS, COMMAND BYTE, AND DATA BYTE FOR DEVICE 2 1 7 1 1 8 1 8 1 Sr SLAVE ADDRESS W A COMMAND CODE A DATA BYTE A UUU KEY: S = START Sr = REPEATED START SLAVE ADDRESS AND SEND BYTE FOR DEVICE 3 1 7 1 1 8 1 Sr SLAVE ADDRESS W A COMMAND CODE A P = STOP W = WRITE BIT (0) UUU A = ACKNOWLEDGE (0) SHADED BLOCK = SLAVE TRANSACTION UUU SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE N 1 7 Sr SLAVE ADDRESS 1 W 1 8 A COMMAND CODE 1 8 A DATA BYTE LOW 寻址 器件接收到自身的固定从地址后，在总线上发出一个应答 (ACK) 进行响应。器件不响应全呼地址，仅在接收到自身 的固定从地址时进行响应。这种操作的唯一例外是ALERT 输出使能 (MFR_MODE中的 ALERT位=1)，并且 ALERT 被触发报警。发生这种状况时，器件仅识别报警响应地址 (0001100,18h)。更多详细信息请参见ALERT 和报警响 应地址(ARA) 部分。 ALERT 和报警响应地址(ARA) 如 果 ALERT 输出使能 (MFR_MODE中的 ALERT位=1)， 发生故障时，器件触发ALERT信号报警输出，然后等待主 1 8 1 1 A DATA BYTE HIGH A P 器件发送报警响应地址 (ARA)，如报警响应地址(ARA) 字 节格式 部分所示。等待 ARA 时，器件不响应自身的固定从 地址。 收到 ARA 后，器件触发ALERT报警，器件对其进行应答， 然后尝试通过仲裁总线将其自身的固定从地址置于总线， 因为其它器件亦可尝试响应 ARA。仲裁规则规定地址最低 的器件获得资格。如果器件赢得仲裁，则解除 ALERT报警， 并开始响应其自身的固定从地址。如果器件仲裁失败，则保 持ALERT的报警状态，等待主器件再次发送 ARA。 17 MAX34441 群发命令 PMBus 5通道电源管理器 和智能风扇控制器 MAX34441 报警响应地址(ARA)字节格式 1 7 S ARA 0001100 1 R 1 8 1 1 A DEVICE SLAVE ADDRESS WITH LSB = 0 NA P 主器件发送或读取的位数太少 主器件在从地址字节中设置的读取状态位错误 当主器件因为任何原因在 START 或 STOP 之前未完成写入一 个完整字节或未能从器件读取一个完整字节，器件将采取以 下动作： 如果器件在命令代码之前收到的从地址中的 R/W位为1，器 件将采取以下动作 ( 注意，不适用于ARA)： 1) 忽略命令。 2) 将 STATUS_BYTE中的 CML位置位。 3) 将 STATUS_WORD 中的 CML位置位。 4) 将 STATUS_CML中的 DATA_FAULT位置位。 5) 通过触发ALERT报警 (若已使能) 通知主器件。 1) 应答地址字节。 2) 只要主器件保持应答，发送全1(FFh)。 3) 将 STATUS_BYTE中的 CML位置位。 4) 将 STATUS_WORD 中的 CML位置位。 5) 将 STATUS_CML中的 DATA_FAULT位置位。 6) 通过触发ALERT报警 (若已使能) 通知主器件。 主器件发送或读取的字节数太少 接收到不支持的命令代码 对于支持的每一条命令，都预期向器件写入或从器件读取固 定数量的字节。如果因为任何原因，写入器件或从器件读取 的字节少于预期数量，器件则完全忽略命令，并不采取任何 动作。 如果主器件向器件发送了不能支持的命令代码，或者当前 PAGE 设置不支持主器件发送的命令代码，器件采取以下 动作： 主器件发送的字节或位数太多 对于支持的每一条命令，都预期向器件写入固定数量的字节。 如果因为任何原因，写入器件的字节或位数多于预期数量， 器件采取以下动作： 1) 忽略命令。 2) 将 STATUS_BYTE中的 CML位置位。 3) 将 STATUS_WORD 中的 CML位置位。 4) 将 STATUS_CML中的 DATA_FAULT位置位。 5) 通过触发ALERT报警 (若已使能) 通知主器件。 主器件读取的字节或位数太多 对于支持的每一条命令，都预期从器件读取固定数量的字 节。如果因为任何原因，从器件读取的字节或位数多于预期 数量，器件采取以下动作： 1) 只要主器件保持应答，发送全1(FFh)。 2) 将 STATUS_BYTE中的 CML位置位。 3) 将 STATUS_WORD 中的 CML位置位。 4) 将 STATUS_CML中的 DATA_FAULT位置位。 5) 通过触发ALERT报警 (若已使能) 通知主器件。 18 1) 忽略命令。 2) 将 STATUS_BYTE中的 CML位置位。 3) 将 STATUS_WORD 中的 CML位置位。 4) 将 STATUS_CML中的 COMM_FAULT位置位。 5) 通过触发ALERT报警 (若已使能) 通知主器件。 接收到无效数据 器件检查 PAGE、OPERATION 和 WRITE_PROTECT命令 代码，确认数据有效。如果主器件写入的数据无效，器件采 取以下动作： 1) 忽略命令。 2) 将 STATUS_BYTE中的 CML位置位。 3) 将 STATUS_WORD 中的 CML位置位。 4) 将 STATUS_CML中的 DATA_FAULT位置位。 5) 通过触发ALERT报警 (若已使能) 通知主器件。 PMBus 5通道电源管理器 和智能风扇控制器 当向一条只写命令 (CLEAR_FAULTS、STORE_DEFAULT_ ALL、RESTORE_DEFAULT_ALL)发出读请求时，器件采 取以下动作： 1) 应答地址字节。 2) 忽略命令。 3) 只要主器件保持应答，发送全1(FFh)。 4) 将 STATUS_BYTE中的 CML位置位。 5) 将 STATUS_WORD 中的 CML位置位。 6) 将 STATUS_CML中的 DATA_FAULT位置位。 7) 通过触发ALERT报警 (若已使能) 通知主器件。 主器件向只读命令请求写操作 当向一条只读命令发出写请求时，器件采取以下动作： 1) 忽略命令。 2) 将 STATUS_BYTE中的 CML位置位。 3) 将 STATUS_WORD 中的 CML位置位。 4) 将 STATUS_CML中的 COMM_FAULT位置位。 5) 通过触发ALERT报警 (若已使能) 通知主器件。 SMBus 超时 如果 SCL在有效工作的 SMBus 通信期间保持为低电平的时 间大于超时周期 ( 通常为 30ms)，器件则终止通信并复位串 行总线。器件不采取其它任何动作，也不设置任何状态位。 PMBus 操作 从软件角度讲，器件为能够执行 PMBus 命令子集的 PMBus 器件。PMBus1.1兼容器件按照 SMBus1.1版协议传输并 响应 SMBus从地 址。本数据资料中，SMBus 指的是按照 SMBus 物理层协议进行通信的 PMBus电气特性，PMBus 代表 PMBus 命令协议。器件采用多种标准的 SMBus 协议(例 如 WriteWord、ReadWord、WriteByte、ReadByte 和 SendByte 等)，设置输出电压和报警 / 故障门限、读取监测 数据，并执行所有制造商规定的命令。 器件支持群发命令。群发命令可以向多个 PMBus 器件发送 命令。它不要求所有器件接收同一命令，但一组命令包只能 向任何一个器件发送一个命令。群发命令不能用于要求接收 器件进行数据响应的指令，例如 STATUS_BYTE 命令。当 器件通过该协议收到命令时，检测到 STOP 条件后将立即执 行收到的命令。 器件支持 PAGE 命令，并可利用该指令选择访问哪一个独立 通道。发送数据字时，先发送低字节，最后发送高字节。任 何一个字节内，先发送最高有效位 (MSB)，最后发送最低有 效位 (LSB)。 PMBus 协议支持 器件支持PMBus™ 电源系统管理协议 规范第II部分 (命令 语言，1.1 版 ) 定义的命令子集。关于规范的详细信息以及 完整的 PMBus 命令列表，请参考 www.PMBus.org 网站发 布的 PMBus 规范第II部分。本文中介绍了所支持的 PMBus 命 令及 对应 的 器 件 操作。除非 特 别说明， 所 有 数 据 都以 DIRECT格式表示。PMBus规范涉及的 PMBus 器件指的是 MAX34441，该器件与一个电源或风扇器件配合工作。由 于命令可能要求打开或关闭 PMBus 器件，MAX34441将始 终保持工作，保持与 PMBus 主器件的通信，MAX34441将 命令发送到相应的电源器件。 数据格式 用于设置或读取输出电压或者是相关参数 ( 如：过压门限 ) 的 电压数据将以 DIRECT格式表示。DIRECT 数据格式是一个 双字节二进制补码。DIRECT 格式数据可用于发送或读取参 数的任何命令。DIRECT 格式利用公式和规定的系数计算相 应数值，表3 所示为器件使用的系数。 19 MAX34441 主器件从只写命令请求读操作 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 表3. PMBus命令代码系数 PARAMETER COMMANDS UNITS RESOLUTION MAX m b R Voltage VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT POWER_GOOD_ON POWER_GOOD_OFF READ_VOUT MFR_VOUT_PEAK MFR_VOUT_MIN mV 1 32,767 1 0 0 Voltage Scaling VOUT_SCALE_MONITOR — 1/32,767 1 32,767 0 0 Current IOUT_OC_WARN_LIMIT IOUT_OC_FAULT_LIMIT READ_IOUT MFR_IOUT_PEAK mA 1 32,767 1 0 0 IOUT_CAL_GAIN mI 0.1 3276.7 1 0 1 OT_FAULT_LIMIT OT_WARN_LIMIT READ_TEMPERATURE_1 MFR_TEMPERATURE_PEAK NC 0.01 327.67 1 0 2 READ_FAN_SPEED_1 FAN_COMMAND_1 MFR_FAN_FAULT_LIMIT MFR_FAN_WARN_LIMIT RPM 1 32,767 1 0 0 FAN_COMMAND_1 MFR_READ_FAN_PWM MFR_FAN_FAULT_LIMIT MFR_FAN_WARN_LIMIT % 0.01 327.67 1 0 2 TON_DELAY TON_MAX_FAULT_LIMIT TOFF_DELAY MFR_FAULT_RETRY ms 1 32,767 1 0 0 Current Scaling Temperature Fan Speed Timing 解析接收到的DIRECT 格式数据 主系统利用下式把从 PMBus 器件 (本例中为 MAX34441) 接 收到的数值转换成伏特、摄氏度或其它单位的读数： X = (1/m) x (Y x 10-R - b) 其中，X为计算值，是对应单位的实际值(V、°C 等) ；m为斜 率系数；Y是从 PMBus 器件接收到的双字节二进制补码表示 的整数；b为偏移量；R为指数。 20 发送DIRECT 格式数据 若要发送一个数据，主器件必须采用下式计算 Y： Y = (mX + b) x 10R 其中，Y为需要发送的双字节二进制补码表示的整数 ；m为 斜率系数；X为待发送的实际数值，带有单位 ( 如：伏特)；b 为偏移量；R为指数。 PMBus 5通道电源管理器 和智能风扇控制器 表4. DIRECT格式数据的系数 COMMAND CODE COMMAND NAME m b R 25h VOUT_MARGIN_HIGH 1 0 0 8Bh READ_VOUT 1 0 0 主 机 发 送 SMBusARA(0001100)。器 件 应 答 SMBus ARA，发送其从地址，并解除 ALERT报警。随后，系统控 制器通过 PMBus 命令进行通信，以便重新获得器件故障 / 报警状态信息。 详细信息请参考各个命令的说明部分。以下任何条件均可清 除被锁存在状态寄存器中的故障和报警标志： • 收到 CLEAR_FAULTS命令。 • 触发RST 引脚。 • 撤除器件偏置电源，然后再重新施加偏置。 如果主器件希望电源输出电压为 3.465V(或 3465mV)，那 么相应的 VOUT_MARGIN_HIGH 值为： 一个或多个闭锁电源只有在发生以下条件之一时才会重启： Y = (1 x 3465 + 0) x 100 = 3465 (十进制) = 0D89h (十六进制) • 通过 CONTROL引脚、OPERATION 命令关闭输出，然 后再打开。 相反，如果主器件在 READ_VOUT命令后收到 0D89h，则 相当于： X = (1/1) x (0D89h x 10-(-0) - 0) = 3465mV = 3.465V 通常，电源和转换器无法了解其输出电路的接地状况。在电 源内部，所有输出电压大多被认为是正电压，所以 PMBus 器件的所有输出电压以及与输出电压相关的参数都以正值设 置和报告。如果系统需要，也可以由系统确定特定的输出为 负值。所有与输出电压相关的命令都采用两个数据字节。 故障管理和报告 为了向 主 器 件 实 时 报 告 故 障 / 报警， 器 件 触 发 漏 极 开 路 ALERT 引脚 ( 如果在 MFR_MODE中被使能)，并将状态寄 存器的相应标识位置位。检测到 ALERT 有效后，主器件或 系统管理器即轮询I2 C总线，以确定触发ALERT的器件。 • 触发RST 引脚。 • 撤除器件偏置电源，然后再重新施加偏置。 如果检测到任何电源响应的故障，则不允许打开电源。只有 清除故障后，才允许打开电源。进行电源全局排序时，任何 电源出现故障都将禁止打开所有电源。 系统整体上电(当 PAGE为 255 时接收到 OPERATION 命令 将电源打开，或者触发CONTROL引脚打开电源)允许所有 使能电源上电。如果电源开始打开时检测到任何故障，执行 MFR_FAULT_RESPONSE 响应。 器件按照制造商的故障响应命令 (MFR_FAULT_RESPONSE) 响应故障条件。该命令字节决定了器件应该如何响应每个具 体故障，表 5所示为具体参数所需的条件和故障动作。 表5. 器件参数监测状态 PARAMETER Overvoltage REQUIRED CONDITIONS FOR ACTIVE MONITORING Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h) Undervoltage • • • Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h) PSEN Output is Active Channel’s VOUT > POWER_GOOD_ON Overcurrent • • Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h) Current Monitoring Enabled (IOUT_OC_FAULT_LIMIT ≠ 0000h) Power-Up Time Overtemperature Fan Speed Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h) Temp Sensor Enabled (ENABLE in MFR_TEMP_SENSOR_CONFIG = 1) Fan Enabled (Bit 7 in FAN_CONFIG_1_2 = 1) ACTION DURING A FAULT Continue Monitoring Stop Monitoring While the Power Supply is Off Continue Monitoring Monitor Only During Power-On Continue Monitoring Continue Monitoring 21 MAX34441 以下举例说明主器件如何发送数据以及从器件如何接收数 据。表 4 所示为以下参数中使用的系数。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 系统看门狗定时器 器件采用内部看门狗定时器，每 5ms 在内部复位一次。如果 器件闭锁并且看门狗定时器在 500ms后尚未复位时，器件 将自动复位。发生复位后，器件重新加载闪存储存的配置值， 并开始正常工作。复位后，器件还采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE位置位。 2) 将 STATUS_WORD 中 的 NONEOFTHEABOVE 和 MFR 位置位。 3) 将 STATUS_MFR_SPECIFIC 中的 WATCHDOG 位置位。 4) 通 过触发ALERT报警 (若在 MFR_MODE中已使能) 通知 主器件。 温度传感器操作 器件可监测多达 6 个不同的温度传感器。它可监测多达 4 个 基于I2 C 的远端温度传感器和一个远端二极管以及自身的 内部温度传感器。每秒钟对每个使能的温度传感器进行一 次测量。远端二极管和内部温度传感器取4 次平均，以降低 噪声影响。器件每次尝试读取温度传感器时都进行故障检 测， 对于 远 端二极管， 读 数 大于 +160 º C 或 小于 -60 º C 时 被认为发生故障。对于内部温度传感器，读数大于 +130 º C 或小于 -60 º C 时被认为发生故障。对于I2 C 温度传感器，通 信失败认为发生故障。通过将温度读数设置为7FFFh 报告 温 度传感 器故障。温 度传感 器故障导 致 STATUS_BYTE 和 STATUS_WORD 中 的TEMPERATURE 位 置 位， 并 触 发ALERT(若 在 MFR_MODE中已使 能) 报 警。不 会 置 位 STATUS_MFR_SPECIFIC 中的任何位。 温度并非必须用来控制风扇转速，可使能并只用于温度监 测。读取被禁用的温度传感器将返回固定值 0000h。 远端二极管温度传感器可采用 npn 或 pnp 晶体管。器件自动 抵消影响远离器件的远端二极管的串联电阻。 器件可控制多达 4 个 DS75LV 数字温度传感器。DS75LV上 的 A0、A1和 A2 引脚应按表 6 所示配置。不使用 DS75LV的 温度调节功能，所以O.S. 输出应保持开路。 22 表6. DS75LV地址引脚配置 DS75LV ADDRESS PIN CONFIGURATION PAGE MAX34441 I2C TEMP SENSOR A2 A1 A0 7 TEMP SENSOR I2C 0 0 0 0 8 0 0 1 9 TEMP SENSOR I2C 1 TEMP SENSOR I2C 2 0 1 0 10 TEMP SENSOR I2C 3 0 1 1 风扇控制操作 风扇控制有 4 种工作模式。模式由 FAN_COMMAND_1 和 FAN_CONFIG_1_2 的第 6 位组合决定(见表 7)。可通过将 FAN_CONFIG_1_2中的第 7位置 0 禁用风扇控制功能。 双风扇应用 RPM 模式下的双风扇应用中，TACHSEL=0 时所选的转速 计被闭环控制到目标 RPM。一旦完成 PWM 调节，TACHSEL 则每 500ms 在两个转速计之间切换，进行监测。READ_ FAN_SPEED_1报告两个转速计信号中的较小数值，并用 于风扇故障和报警的比较。PWM 模式下的双风扇应用中， TACHSEL 总是每 500ms 进行一次切换。如果两路转速计 信号中的某路信号工作速率较低，建议将较慢的转速计在 TACHSEL=0 时送至 TACH 输入。 自动风扇控制操作 自动模式下，根据控制温度 ( 归一化后最高温度读数 ) 和相 应的风扇控制 PWM占空比(单位为 %) 或风扇转速 (单位为 RPM)对风扇进行闭环控制。这些参数均在风扇查找表(LUT) 中指定，详细配置信息请参见 MFR_FAN_LUT说明。控制 温度超过 LUT中设置的温度水平时，器件根据与该温度相 关的信息输出 PWM占空比或调节风扇转速，图1给出了一个 示例。 PMBus 5通道电源管理器 和智能风扇控制器 FAN CONTROL MODE FAN OPERATIONAL DETAILS BIT 6 OF _ FAN_CONFIG_1_2 VALUE IN _ FAN_COMMAND_1 Manual PWM External host controls the fan speed by directly setting the fan PWM duty cycle values. 0 0000h to 7FFFh Manual RPM External host controls the fan speed by setting target fan speed values. The device reads the actual fan speed, and close loop adjusts the output fan PWM to match the target fan speed. 1 0000h to 7FFFh Automatic PWM The device sets the output PWM based on the fan LUT that maps the temperature sensor readings to the required fan PWM duty-cycle values. 0 8000h to FFFFh Automatic RPM The device reads the actual fan speed and close loop adjusts the output fan PWM to match the target fan speed based on the fan LUT that maps the temperature sensor readings to the required fan speed. 1 8000h to FFFFh 注：RPM 模式应只用于提供转速计输出的风扇。 OFFSET ADJUSTMENT ALLOWS TEMPERATURE ZONE NORMALIZATION PAGE 7 I2C REMOTE TEMP SENSOR 0 +15°C PAGE 8 I2C REMOTE TEMP SENSOR 1 +10°C PAGE 9 I2C REMOTE TEMP SENSOR 2 0°C PAGE 10 I2C REMOTE TEMP SENSOR 3 0°C FAN 8 LEVEL LOOKUP TABLE FAN HIGHEST TEMPERATURE CONTROLS THE FAN PAGE 11 REMOTE DIODE TEMP SENSOR +5°C PAGE 6 INTERNAL TEMP SENSOR +5°C 图1. 自动风扇控制 23 MAX34441 表7. 风扇控制工作模式 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 6 个温度传感器的任意一个或所有温度传感器均可用于控制 风扇转速。每个温度传感器均具有温度偏移调节，允许监测 具有不同温度特性的温度区域。图1中，I2 C 温度传感器 0 监 测的区域比I2 C 温度传感器 3 测量的区域敏感15º C。为了把 可闻噪声和风扇功耗降至最低，器件允许每路温度传感器 增加一个温度偏移。从而允许通过具有不同温度特性的温度 区域控制风扇，使其保持在尽可能低的转速，维持所要求 的温度范围。 的 PWM目标值之前没有达到目标值，器件将停止向原目标 值移动，并按照所设置的调节速率开始向新目标值移动。 如果没有指定温度传感器用于风扇控制，输出风扇 PWM 信 号将被调至最高100% 的占空比。 脉冲展宽 在一些 3 线风扇应用中，当中断电源控制风扇转速时，转速 计信号不可用。有些风扇控制器周期性展宽 PWM 信号，以 允许精确检测转速计，展宽脉冲会产生可闻噪声。该器件 不支持脉冲展宽。由于RPM 风扇模式始终需要一个可靠的 转速计信号，所以不适合通过切换风扇电源控制转速的应 用。例如，3 线风扇的低边切换不应使用任何一种 RPM 风扇 模式。 图 2 中，在温度采样点1，所要求的风扇转速对应于温度等 级 2 的转速水平，由于温度采样点1的温度高于温度等级3， 需要增大风扇 PWM占空比，以提高风扇转速。器件提高风 扇 PWM占空比的速率由 MFR_FAN_CONFIG 命令代码中的 RAMP 位控制。如果 PWM占空比在温度采样检测到需要新 在温度采样点 2，温度已升高至温度等级4 以上，所以必须 再次增大 PWM占空比。在温度采样点 3，温度已下降，但 未低于温度滞回(由 MFR_FAN_CONFIG 命令代码中的 HYS 位设置 )，所以风扇转速仍保持在 4 级。在温度采样点4，温 度已下降至滞回温度以下，所以降低了 PWM占空比。 SENSOR TEMPERATURE FAN SPEED T7 S7 T6 THERMAL HYSTERESIS SAMPLED TEMPERATURES T5 S5 SAMPLE 2 SAMPLE 3 T4 T3 S4 SAMPLE 1 SAMPLE 4 S3 T2 S2 T1 S1 T0 S0 ELAPSED TIME TEMPERATURE SAMPLE RATE (ONCE PER SECOND) 图2. 风扇速度示例 24 S6 PMBus 5通道电源管理器 和智能风扇控制器 图 3 所示为风扇上旋过程。风扇上旋时，每 200ms 检测一次 转数，持续长达 2s 的时间。当转数高于或等于宽松的上旋 标准时，风扇通过上旋。如果风扇具有锁定转子输出，没有 触发锁定转子信号时风扇通过上旋。 100% SPIN-UP CRITERIA MET AUTOMATIC SPIN-UP ENABLED 90% 通过上旋时，器件强制风扇 PWM占空比为 40%。40% 的占 空比将保持到完成下次温度转换 (每秒转换一次 )。温度转 换后，器件进入手动模式工作或按照 MFR_FAN_LUT自动 工作。 80% 70% RAMP PWM TO TARGET PWM OR RPM (CONSTRAINED BY THE RAMP BITS) 60% 50% 40% AUTOMATIC SPIN-UP DISABLED 30% ALWAYS RETURN TO 40% DUTY CYCLE AFTER AUTOMATIC SPIN-UP BEFORE BEGINNING PWM RAMP (EVEN IF BEYOND 1 SECOND) 20% INITIAL TARGET PWM OR RPM DETERMINED AFTER TEMPERATURE CONVERSION 10% 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 TIME (SECONDS) 图3. 风扇上旋 25 MAX34441 风扇上旋 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 PMBus命令 以下部分汇总介绍器件所支持的 PMBus 命令。 PAGE (00h) 器件可利用一个 PMBus(I2 C) 地址控制多达 5 路电源、6 个温度传感器和1个风扇。发送数据 0至11的 PAGE 命令选择受控于 表1所有 PMBus 命令的电源、温度传感器或风扇。并非每页都支持所有命令。如果接收到不支持的命令，CML 状态位被置位。 有些命令为通用命令，意味着任意选择页都具有相同影响，并且器件具有相同响应。 如果希望以下 PMBus 命令同时作用于所有页，将 PAGE 设置为 255。该功能只对少数命令 (OPERATION、CLEAR_FAULTS) 具有实际意义。 表8. 页命令 PAGE (DEC) Power Supply Connected to ADC 0 1 Power Supply Connected to ADC 1 2 Power Supply Connected to ADC 2 3 Power Supply Connected to ADC 3 4 Power Supply Connected to ADC 4 5 Fan Connected to PWM 5 6 Internal Temperature Sensor 7 Remote I2C Temperature Sensor with Address 0 8 Remote I2C Temperature Sensor with Address 1 9 Remote I2C Temperature Sensor with Address 2 10 Remote I2C Temperature Sensor with Address 3 11 12 to 254 255 26 ASSOCIATED CONTROL 0 Remote Thermal-Diode Sensor Reserved Applies to All Pages PMBus 5通道电源管理器 和智能风扇控制器 用户提示：所有被标记为 GLOBAL 的电源 ( 参见 MFR_FAULT_RESPONSE) 应同时打开和关闭。 表9. OPERATION命令字节(ON_OFF_CONFIG的第3位 = 1时) COMMAND BYTE POWER SUPPLY ON OR OFF MARGIN STATE 00h Immediate Off (No Sequencing) N/A 40h Soft Off (with Sequencing) N/A 80h On Margin Off 94h On Margin Low (Ignore All Faults) 98h On Margin Low (Act On Any Fault) A4h On Margin High (Ignore All Faults) A8h On Margin High (Act On Any Fault) 注：器件只有在电源使能时才采取动作。所有被使能通道的VOUT必须超过 POWER_GOOD_ON 才能开始调节裕量。 表10. OPERATION命令字节(ON_OFF_CONFIG的第3位 = 0 时) COMMAND BYTE POWER SUPPLY ON OR OFF MARGIN STATE 00h Command Has No Effect N/A 40h Command Has No Effect N/A 80h Command Has No Effect Margin Off 94h Command Has No Effect Margin Low (Ignore All Faults) 98h Command Has No Effect Margin Low (Act On Any Fault) A4h Command Has No Effect Margin High (Ignore All Faults) A8h Command Has No Effect Margin High (Act On Any Fault) 注：器件只有在电源使能时才采取动作。所有被使能通道的VOUT必须超过 POWER_GOOD_ON 才能开始调节裕量。 27 MAX34441 OPERATION (01h) OPERATION 命令配合 CONTROL 输入引脚打开和关闭电源。OPERATION 命令还可以把电源的输出电压设置在较高或较低 裕量。在新的 OPERATION 命令或 CONTROL引脚 ( 如果使能) 状态变化使电源更改到另一状态之前，电源将维持命令指定的 工作模式，有效的 OPERATION 命令字节数值请参考表 9 和表10。OPERATION 命令在收到更改输出的命令后控制器件的响 应操作。当命令字节为 00h 时，器件立即关断电源，并忽略所有关断延时设置。当命令字节设置为 40h 时，器件则根据所设 置的关断延时关断电源。在表 9 和表10 中， “actonanyfault”表示当进行输出裕量调节时，如果在所选电源上检测到任何报 警或故障，器件将其视为报警或故障，并根据设置进行响应。 “Ignoreallfaults”表示忽略所选电源的所有报警和故障。表 9 和表10 中没有列出的任何其它命令值均为无效命令。如果器件收到表 9 和表10 中没有列出的数据字节，则将其视为无效数据， 报告数据故障 ( 置位 CML位，触发ALERT)，并按照故障管理和报告 部分的说明进行响应。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 ON_OFF_CONFIG (02h) ON_OFF_CONFIG 命令用于配置 CONTROL 输入和 PMBusOPERATION 命令，以便开启、关闭电源。该命令指示上电时如 何控制电源，表11所示为 ON_OFF_CONFIG 消息内容。主器件在电源有效时不应修改 ON_OFF_CONFIG。 表11. ON_OFF_CONFIG (02h)命令字节 BIT 7:5 4 3 PURPOSE Reserved N/A Turn on supplies when bias is present or use the CONTROL pin and/or OPERATION command OPERATION Command Enable 2 CONTROL Pin Enable 1 CONTROL Pin Polarity 0 BIT VALUE CONTROL Pin Turn-Off Action MEANING Always returns 000. 0 Turn on the supplies (with sequencing, if so configured) as soon as bias is supplied to the device regardless of the CONTROL pin. 1 Operate the supplies as instructed by the CONTROL pin and/or the OPERATION command. 0 Ignore the on/off portion of the OPERATION command. 1 OPERATION command enabled and required for action. 0 Ignore the CONTROL pin. 1 CONTROL pin enabled and required for action. 0 Active low (drive low to turn on the power supplies). 1 Active high (drive high to turn on the power supplies). 0 Use the programmed turn-off delay (soft off). 1 Turn off the power supplies immediately. CLEAR_FAULTS (03h) CLEAR_FAULTS命令用于清除状态寄存器中被置位的所有故障或警告位，该命令同时清除所有位。CLEAR_FAULTS命令 不会使由于故障条件而闭锁的电源重新启动。PSEN 在故障条件下的状态不受该命令的影响，只有通过 OPERATION 命令或 CONTROL引脚才能改变。如果执行 CLEAR_FAULTS命令后仍然存在故障，则故障状态位重新置位并再次触发ALERT报警 (若在 MFR_MODE中已使能)，通知主器件。该命令为只写命令，无数据字节。 WRITE_PROTECT (10h) WRITE_PROTECT命令用来保护器件在工作状态下不会意外改写存储器内容。所有支持命令均由对应的参数读取，与 WRITE_PROTECT 设置无关，表12 给出了WRITE_PROTECT的信息内容。 表12. WRITE_PROTECT命令字节 COMMAND BYTE MEANING 80h Disable all writes except the WRITE_PROTECT command. 40h Disable all writes except the WRITE_PROTECT, OPERATION, and PAGE commands. 20h Disable all writes except the WRITE_PROTECT, OPERATION, PAGE, and ON_OFF_CONFIG commands. 00h Enable writes for all commands (default). 注：如果主器件试图写入受保护区域，不会产生故障或错误。 28 PMBus 5通道电源管理器 和智能风扇控制器 用户提示：VDD 必须高于 2.9V ，器件才能执行 STORE_DEFAULT_ALL 命令。 RESTORE_DEFAULT_ALL (12h) RESTORE_DEFAULT_ALL命令从内部闪存阵列中发送默认配置信息至器件中的用户存储寄存器。只有器件没有操控电源或 风扇时才执行 RESTORE_DEFAULT_ALL命令。器件复位时，无需 PMBus 动作，器件自动执行该命令。该命令为只写命令， 无数据字节。 CAPABILITY (19h) CAPABILITY命令用来确定器件的一些重要功能。CAPABILITY命令为只读，表13 给出了信息内容的说明。 表13. CAPABILITY命令字节 BIT 7 6:5 4 3:0 DESCRIPTION MEANING Packet-Error Checking 0 = PEC not supported. PMBus Speed 00 = Maximum supported bus speed is 100kHz. ALERT 1 = Device supports an ALERT output (if ALERT is enabled in MFR_MODE). 0 = Device does not support ALERT output (ALERT is disabled in MFR_MODE). Reserved Always returns 0000. VOUT_MODE (20h) VOUT_MODE 命令用来报告器件的数据格式。器件对于所有与电压相关的命令均采用 DIRECT 格式。返回值为 40h ，表示 DIRECT 数据格式。该命令为只读命令，如果主器件试图写该命令，CML 状态位置位。不同命令对应的 m、b 和 R 值请参考 表 3。 VOUT_MARGIN_HIGH (25h) VOUT_MARGIN_HIGH 命令向器件装载一个电压值，当 OPERATION 命令设置为裕量上限时，电源输出将更改为该电压值。 如果电源已经工作在裕量上限，改变 VOUT_MARGIN_HIGH 不会影响输出电压。器件只是在收到新的 OPERATION 裕量上 限调节命令时才会把电源调节到新的 VOUT_MARGIN_HIGH 电压。双数据字节采用 DIRECT 格式，如果器件不能成功闭环调 节电源裕量，器件则保持尝试调节电源裕量，并采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 和 MFR 位置位。 3) 将 STATUS_MFR_SPECIFIC 中的 MARGIN_FAULT位置位。 4) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 29 MAX34441 STORE_DEFAULT_ALL (11h) STORE_DEFAULT_ALL命令使器件将器件配置信息发送至内部闪存阵列，并非存储所有信息。只储存配置信息，并非所有 状态信息或工作数据。如果在传输期间发生错误，则触发ALERT( 如果已使能)，STATUS_BYTE 和 STATUS_WORD 中的 CML位被置1，不会对 STATUS_CML中的任何位置位。当器件在操作电源或风扇时，不建议使用 STORE_DEFAULT_ALL 命 令。传输配置时，器件不响应 PMBus 命令，并且不监测电源。该命令为只写命令，无数据字节。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 VOUT_MARGIN_LOW (26h) VOUT_MARGIN_LOW 命令向器件装载一个电压值，当 OPERATION 命令设置为裕量下限时，电源输出将更改为该电压值。 如果电源已经工作在裕量下限，改变 VOUT_MARGIN_LOW 不会影响输出电压。器件只是在收到新的 OPERATION 裕量下限 调节命令时才会把电源调节到新的 VOUT_MARGIN_LOW电压。双数据字节采用 DIRECT 格式，如果器件不能成功地闭环调 节电源裕量，器件则保持尝试调节电源裕量，并采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 和 MFR 位置位。 3) 将 STATUS_MFR_SPECIFIC 中的 MARGIN_FAULT位置位。 4) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 VOUT_SCALE_MONITOR (2Ah) VOUT_SCALE_MONITOR用于实测电源电压不等于ADC 输入电压的应用。例如，输出为12V 时，ADC 输入电压为1.0V， VOUT_SCALE_MONITOR=1.0V/12V=0.0833。在电源输出电压大于器件输入范围的应用中，通过一个电阻分压器 检测电源输出电压。电阻分压器可以降低或调节输出电压。PMBus 命令规定了实际的电源输出电压，而非 ADC 的输入电 压。若要器件在电源电压(例如12V) 和 ADC 输入电压之间进行映射，则使用 VOUT_SCALE_MONITOR 命令。双数据字节 采用 DIRECT 格式，该数值没有单位。例如，如果所需的比例因子为 0.0833，VOUT_SCALE_MONITOR 应设为 0AABh (2731/32,767=0.0833)。 表14. VOUT_SCALE_MONITOR NOMINAL VOLTAGE LEVEL NOMINAL ADC INPUT VOLTAGE MONITORED (V) LEVEL (V) (SEE NOTE) RESISTIVE VOLTAGEDIVIDER RATIO VOUT_SCALE_MONITOR VALUE (HEX) 6AAAh 1.2 1.0 0.833 1.5 1.0 0.667 5555h 1.8 1.0 0.555 470Ah 2.5 1.0 0.4 3333h 3.3 1.0 0.303 26C8h 5 1.0 0.2 1999h 12 1.0 0.0833 0AABh 注：器件的满量程 ADC 电压为1.225V。建议通过比例因子使1.0VADC 输入对应100% 标称电压。 IOUT_CAL_GAIN (38h) IOUT_CAL_GAIN 命令用于设置ADC 输入电压与检测电流的比值。IOUT_CAL_GAIN 系数的单位为 0.1mΩ。双数据字节采 用 DIRECT格式，例如，如果使用10mΩ 检流电阻和 50V/V电流检测放大器，IOUT_CAL_GAIN 应设为 500mΩ 或1388h。 用户提示：器件的满量程 ADC 电压为 1.225V ，必须适当调节检流电阻和电流检测放大器增益。 30 PMBus 5通道电源管理器 和智能风扇控制器 表15. FAN_CONFIG_1_2 命令字节 BIT NAME 7 FAN ENABLE 6 RPM/PWM 5:4 PULSE 3:0 0 MEANING 0 = Fan disabled (PWM5 forced low). 1 = Fan enabled. 0 = PWM duty cycle is the fan-controlling parameter. 1 = RPM is the fan-controlling parameter. 00 01 10 11 = = = = 1 2 3 4 Tach Tach Tach Tach pulse per fan revolution. pulses per fan revolution. pulses per fan revolution. pulses per fan revolution. These bits always return a 0. FAN_COMMAND_1 (3Bh) FAN_COMMAND_1 命令用于屏蔽器件的自动风扇控制功能，并 把风扇强制在固定 PWM占空比或目标风扇转速(单位 为 RPM)。FAN_COMMAND_1 的 单位 为占 空 比 的百分 数 ( 如 果 FAN_CONFIG_1_2 的 第 6 位 为 0) 或 RPM( 如 果 FAN_ CONFIG_1_2 的第 6 位为1)。低于 0%占空比或 0RPM 的任何值都将使器件忽略该命令，并采用自动风扇控制功能。大于或 等于 0%占空比或 0RPM 的任何值都将使器件忽略自动风扇控制，并强制风扇至 FAN_COMMAND_1命令提供的 PWM 值或 RPM 值。双数据字节采用 DIRECT格式。 表16. PWM风扇模式(FAN_CONFIG_1_2的第6位 = 0) FAN_COMMAND_1 VALUE DEVICE RESPONSE 8000h to FFFFh Ignore FAN_COMMAND_1 and use automatic fan-control function 0000h to 2710Fh 0 to 100% fan PWM duty cycle 2711h to 7FFFh 100% fan PWM duty cycle 表17. RPM风扇模式(FAN_CONFIG_1_2的第6位 = 1) FAN_COMMAND_1 VALUE DEVICE RESPONSE 8000h to FFFFh Ignore FAN_COMMAND_1 and use automatic fan-control function 0000h to 7FFFh 0 to 32,767 RPM 31 MAX34441 FAN_CONFIG_1_2 (3Ah) FAN_CONFIG_1_2 命令与 MFR_FAN_CONFIG 共同配置风扇，关于该命令的更多详细信息请参考MFR_FAN_CONFIG (F1h) 部分，关于 FAN_CONFIG_1_2 命令的说明请参考表15。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 VOUT_OV_FAULT_LIMIT (40h) VOUT_OV_FAULT_LIMIT命令用于设置输出过压故障对应的输出电压值。双数据字节采用 DIRECT格式，当输出电压超过 VOUT_OV_FAULT_LIMIT 时，器件将采取以下动作： 1) 将 STATUS_BYTE中的 VOUT_OV位置位。 2) 将 STATUS_WORD 中的 VOUT_OV 和 VOUT位置位。 3) 将 STATUS_VOUT中的 VOUT_OV_FAULT位置位。 4) 根据 MFR_FAULT_RESPONSE中的设置进行响应。 5) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 VOUT_OV_WARN_LIMIT (42h) VOUT_OV_WARN_LIMIT命令用于设置输出高压报警对应的输出电压值。该值通常小于VOUT_OV_FAULT_LIMIT的输出电 压门限。双数据字节采用 DIRECT格式，当输出电压超过 VOUT_OV_WARN_LIMIT 时，器件将采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 和 VOUT位置位。 3) 将 STATUS_VOUT中的 VOUT_OV_WARN 位置位。 4) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 VOUT_UV_WARN_LIMIT (43h) VOUT_UV_WARN_LIMIT命令用于设置输出低压报警对应的输出电压值。该值通常高于VOUT_UV_FAULT_LIMIT的输出 欠压故障门限。启动时，该报警值在输出电压达到所设置的 POWER_GOOD_ON 电压之前被屏蔽，并且在电源禁用的关断期 间也被屏蔽。双数据字节采用 DIRECT格式，当输出电压低于VOUT_UV_WARN_LIMIT 时，器件将采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 和 VOUT位置位。 3) 将 STATUS_VOUT中的 VOUT_UV_WARN 位置位。 4) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 VOUT_UV_FAULT_LIMIT (44h) VOUT_UV_FAULT_LIMIT命令用于设 置输出欠压故障对应的输出电压值。启动时，该故障在输出电压 达 到所 设 置的 POWER_GOOD_ON 电压之前被屏蔽，并且在电源禁用的关断期间也被屏蔽。VOUT_UV_FAULT_LIMIT门限亦用于确定是 否超过 TON_MAX_FAULT_LIMIT。双数据字节采用 DIRECT 格式，当输出电压低于VOUT_UV_FAULT_LIMIT 时，器件将 采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 和 VOUT位置位。 3) 将 STATUS_VOUT中的 VOUT_UV_FAULT位置位。 4) 根据 MFR_FAULT_RESPONSE中的设置进行响应。 5) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 32 PMBus 5通道电源管理器 和智能风扇控制器 IOUT_OC_FAULT_LIMIT (4Ah) IOUT_OC_FAULT_LIMIT命令用于设置输出过流故障对应的电流值。IOUT_OC_FAULT_LIMIT的工厂默认值为 0000h， 该值禁止器件测量电流。写入至IOUT_OC_FAULT_LIMIT的任意非零正值都将使能器件的电流测量功能。双数据字节采用 DIRECT格式，当输出电流超过IOUT_OC_FAULT_LIMIT 时，器件将采取以下动作： 1) 将 STATUS_BYTE中的IOUT_OC位置位。 2) 将 STATUS_WORD 中的IOUT、IOUT_OC 和 MFR 位置位。 3) 将 STATUS_MFR_SPECIFIC 中的 OC_FAULT位置位。 4) 根据 MFR_FAULT_RESPONSE中的设置进行响应。 5) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 表18. IOUT_OC_FAULT_LIMIT IOUT_OC_FAULT_LIMIT VALUE 8000h to FFFFh DEVICE RESPONSE (ON THE ASSOCIATED PAGE) Negative values are invalid. 0000h Current measurement disabled. 0001h to 7FFFh Current measurement enabled. OT_FAULT_LIMIT (4Fh) OT_FAULT_LIMIT命令用来设置导致器件发生高温故障时对应的温度传感器的温度值，单位为摄氏度。双数据字节采用 DIRECT格式，当温度超过 OT_FAULT_LIMIT 时，器件将采取以下动作： 1) 将 STATUS_BYTE中的TEMPERATURE 位置位。 2) 将 STATUS_WORD 中的TEMPERATURE 和 MFR 位置位。 3) 将 STATUS_MFR_SPECIFIC 中的 OT_FAULT位置位。 4) 根据 MFR_FAULT_RESPONSE中的设置进行响应。 5) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 33 MAX34441 IOUT_OC_WARN_LIMIT (46h) IOUT_OC_WARN_LIMIT命令用于设置输出过流报警对应的电流值。该值通常小于IOUT_OC_FAULT_LIMIT的过流故障门 限。双数据字节采用 DIRECT格式，当输出电流超过IOUT_OC_WARN_LIMIT 时，器件将采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE、IOUT 和 MFR 位置位。 3) 将 STATUS_MFR_SPECIFIC 中的 OC_WARN 位置位。 4) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 OT_WARN_LIMIT (51h) OT_WARN_LIMIT命令用来设置导致器件发生高温报警时对应的温度传感器的温度值，单位为摄氏度。双数据字节采用 DIRECT格式，当温度超过 OT_WARN_LIMIT 时，器件将采取以下动作： 1) 将 STATUS_BYTE中的TEMPERATURE 位置位。 2) 将 STATUS_WORD 中的TEMPERATURE 和 MFR 位置位。 3) 将 STATUS_MFR_SPECIFIC 中的 OT_WARN 位置位。 4) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 POWER_GOOD_ON (5Eh) POWER_GOOD_ON 命令设置导致 PG 输出(若已在 MFR_MODE中使能)变为有效时对应的输出电压值。所有被使能电源必 须高于其对应的 POWER_GOOD_ON 门限，PG 输出才能有效。所有被使能电源也必须高于 POWER_GOOD_ON，才能开 始调节电源裕量。POWER_GOOD_ON 通常设为高于 POWER_GOOD_OFF 和 VOUT_UV_FAULT_LIMIT。双数据字节采用 DIRECT格式。 POWER_GOOD_OFF (5Fh) POWER_GOOD_OFF 命令设置在 PG 输出(若已在 MFR_MODE中使能) 有效后使其变为无效时对应的输出电压值。当任何被 使能电源的电压下降到对应的 POWER_GOOD_OFF门限以下时都将导致 PG 输出无效。POWER_GOOD_OFF电压通常设置 在低于 POWER_GOOD_ON 的数值。双数据字节采用 DIRECT格式。 当电源的 VOUT从高于 POWER_GOOD_ON 下降到低于 POWER_GOOD_OFF 时，STATUS_WORD 和 STATUS_MFR_ SPECIFIC 中的 POWER_GOOD# 位被置位。 OPERATION COMMAND CODE OR CONTROL PIN TON_DELAY TOFF_DELAY PSEN PIN (ACTIVE HIGH OR LOW/ OPEN DRAIN OR PUSH-PULL) TON_MAX_FAULT_LIMIT POWER_GOOD_ON VOUT_UV_FAULT_LIMIT ADC INPUT POWER_GOOD# BIT IN STATUS_MFR_SPECIFIC 图4. 电源排序 34 POWER_GOOD_OFF PMBus 5通道电源管理器 和智能风扇控制器 TON_MAX_FAULT_LIMIT (62h) TON_MAX_FAULT_LIMIT 设置从触发TON_DELAY 和 PSEN 输出到输出电压跨过 VOUT_UV_FAULT_LIMIT门限的时间 上限，单位为毫秒。双数据字节采用 DIRECT格式，如果该值为 0，器件不对电源排序，不会触发 PSEN 输出指示，并且禁用 电压和电流监测。超过 TON_MAX_FAULT_LIMIT 时，器件将采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 和 VOUT位置位。 3) 将 STATUS_VOUT中的TON_MAX_FAULT位置位。 4) 根据 MFR_FAULT_RESPONSE中的设置进行响应。 5) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 表19. TON_MAX_FAULT_LIMIT TON_MAX_FAULT_LIMIT VALUE 8000h to FFFFh 0000h DEVICE RESPONSE (FOR THE ASSOCIATED PAGE) Negative values are invalid. Channel off (PSEN remains deasserted with no monitoring). 0001h to 7FFFh Channel on and sequencing enabled. TOFF_DELAY (64h) TOFF_DELAY 设置从收到 STOP 条件 (软关断 OPERATION 命令或通过使能的 CONTROL引脚)到解除 PSEN 输出需要的时 间，单位为毫秒。当设置为立即关断 ( 通过 OPERATION 命令或 CONTROL引脚) 时，将忽略 TOFF_DELAY。双数据字节采用 DIRECT格式。 STATUS_BYTE (78h) STATUS_BYTE 命令返回1个字节的信息，内容为最关键的故障总结。数值1表示已经发生故障或报警 ；数值 0 则相反。对 于不支持的功能标识位，返回 0。STATUS_BYTE 不能通过 RESTORE_DEFAULT_ALL命令恢复，表 20 给出了STATUS_ BYTE 的信息内容，该命令为只读命令。 表 20. STATUS_BYTE BIT BIT NAME 7:6 0 5 VOUT_OV 4 IOUT_OC 3 0 2 TEMPERATURE 1 CML 0 MEANING These bits always return a 0. An overvoltage fault has occurred. An overcurrent fault has occurred. This bit always returns a 0. A temperature fault or warning has occurred. A communication, memory, or logic fault has occurred. NONE OF THE ABOVE A fault or warning not listed in bits [7:1] has occurred. 35 MAX34441 TON_DELAY (60h) TON_DELAY 设置从收到 START条件 (有效的 OPERATION 命令或通过使能的 CONTROL引脚)到触发 PSEN 输出需要的时间， 单位为毫秒。在 TON_DELAY 期间屏蔽欠压故障和报警。双数据字节采用 DIRECT格式。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 STATUS_WORD (79h) STATUS_WORD 命令返回2个字节的信息，内容为对故障原因的总结。STATUS_WORD 的低字节与 STATUS_BYTE 数据相 同，表 21所示为 STATUS_WORD 消息内容。 表 21. STATUS_WORD BIT BIT NAME 15 VOUT An output voltage fault or warning or TON_MAX_FAULT has occurred. 14 IOUT An overcurrent fault or warning has occurred. 13 0 12 MFR 11 POWER_GOOD# 10 FANS MEANING This bit always returns a 0. A bit in STATUS_MFR_SPECIFIC has been set. A power-supply voltage has fallen from POWER_GOOD_ON to less than POWER_GOOD_OFF. A fan fault has occurred. 9:6 0 5 VOUT_OV An overvoltage fault has occurred. 4 IOUT_OC An overcurrent fault has occurred. 3 0 2 TEMPERATURE 1 CML 0 These bits always return a 0. This bit always returns a 0. A temperature fault or warning has occurred. A communication, memory, or logic fault has occurred. NONE OF THE ABOVE A fault or warning not listed in bits [7:1] has occurred. STATUS_VOUT (7Ah) STATUS_VOUT命令返回1个字节的信息，内容说明请参见表 22。 表 22. STATUS_VOUT BIT BIT NAME 7 VOUT_OV_FAULT VOUT overvoltage fault. MEANING 6 VOUT_OV_WARN VOUT overvoltage warning. 5 VOUT_UV_WARN VOUT undervoltage warning. 4 VOUT_UV_FAULT VOUT undervoltage fault. 3 0 2 TON_MAX_FAULT 1:0 0 This bit always returns a 0. TON maximum fault. These bits always return a 0. STATUS_CML (7Eh) STATUS_CML命令返回1个字节的信息，内容说明请参见表 23。 表 23. STATUS_CML 36 BIT BIT NAME 7 COMM_FAULT An invalid or unsupported command has been received. 6 DATA_FAULT An invalid or unsupported data has been received. 5:1 0 0 FAULT_LOG_FULL MEANING These bits always return a 0. MFR_NV_FAULT_LOG is full and needs to be cleared. PMBus 5通道电源管理器 和智能风扇控制器 表 24. STATUS_MFR_SPECIFIC BIT BIT NAME 7 OFF 6 OT_WARN 5 OT_FAULT 4 WATCHDOG MEANING This bit is set if the power supply is off (due to either a fault or sequencing delay; this bit is not set if the power supply is disabled). Overtemperature warning. Overtemperature fault. A watchdog reset has occurred. 3 MARGIN_FAULT This bit is set if the device cannot properly close-loop margin the power supply. 2 POWER_GOOD# Power-supply voltage has fallen from POWER_GOOD_ON to less than POWER_GOOD_OFF. 1 OC_FAULT IOUT overcurrent fault. 0 OC_WARN IOUT overcurrent warning. 注：OFF 和 POWER_GOOD# 位的设置不会触发ALERT信号。 STATUS_FANS_1_2 (81h) STATUS_FANS_1_2 命令返回1个字节的信息，内容为风扇状态指示，关于STATUS_FANS_1_2 命令的说明请参考表 25。 表 25. STATUS_FANS_1_2 BIT BIT NAME 7 FAN_1_FAULT 6 0 5 FAN_1_WARN 4:0 0 MEANING Fan 1 fault. This bit always returns a 0. Fan 1 warning. These bits always return a 0. READ_VOUT (8Bh) READ_VOUT命令返回实际测得 (而不是设置 ) 的输出电压。每 5ms 进行一次测量并更新 READ_VOUT。双数据字节采用 DIRECT格式。 READ_IOUT (8Ch) READ_IOUT命令返回最新测得的电流值。每200ms 进行一次测量并更新 READ_IOUT。双数据字节采用 DIRECT格式。 READ_TEMPERATURE_1 (8Dh) READ_TEMPERATURE_1命令 返回从 温度传感器测得的温度值。READ_TEMPERATURE_1数值不包括 MFR_TEMP_ SENSOR_CONFIG 增加的偏移量。如果发生传感器故障，READ_TEMPERATURE_1返回 7FFFh ；如果禁用传感器，则返回 0000h。每秒进行一次测量并更新 READ_TEMPERATURE_1。双数据字节采用 DIRECT格式。 37 MAX34441 STATUS_MFR_SPECIFIC (80h) STATUS_MFR_SPECIFIC命令返回1个字节的信息，内容为对故障原因的总结。STATUS_MFR_SPECIFIC信息内容的说明 请参见表 24。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 READ_FAN_SPEED_1 (90h) READ_FAN_SPEED_1命令返回风扇转速，单位为 RPM。即使风扇被禁用，也每秒更新 READ_FAN_SPEED_1。必须正确 配置 FAN_CONFIG_1_2 中的 PULSE 位，才能接收正确的风扇转速。低于 60RPM(双模式风扇为360RPM) 的风扇转速被 报告为 0RPM。双数据字节采用 DIRECT格式。 PMBUS_REVISION (98h) PMBUS_REVISION 命令返回器件兼容的 PMBus规范版本号。该命令包含一个数据字节，[7:4] 位表示器件兼容的 PMBus规 范第I部分的版本号；[3:0] 位表示器件兼容的 PMBus 规范第II部分的版本号。该命令为只读命令，PMBUS_REVISION 的返回 值始终为11h，表示器件兼容于规范第I部分的1.1版本和第II部分的1.1版本。 MFR_ID (99h) MFR_ID 命令返回制造商(Maxim) 标识符的文本(ISO/IEC8859-1) 字符。MFR_ID 的默认值为4Dh(M)。该命令为只读命令。 MFR_MODEL (9Ah) MFR_MODEL 命令返回器件模型编号的文本 (ISO/IEC8859-1) 字符。MFR_MODEL 的默认值为 52h(R)。该命令为只读 命令。 MFR_REVISION (9Bh) MFR_REVISION 命 令 返 回 两 个文 本(ISO/IEC8859-1)字 符， 包 括 器 件 硬 件 (高 字 节) 和 固 件 (低 字 节)版 本号。MFR_ REVISION 的默认值为3030h(00)。该命令为只读命令。 MFR_LOCATION (9Ch) MFR_LOCATION 命令为器件装载用于识别电源制造厂商的文本(ISO/IEC8859-1)字符，最大字符数为 8。可采用 STORE_ DEFAULT_ALL命令将该数据写入内部闪存。工厂默认字符串值为3130313031303130h。 MFR_DATE (9Dh) MFR_DATE 命令为器件装载用于识别电源制造日期的文本(ISO/IEC8859-1)字 符，最 大字 符 数为 8。可采用 STORE_ DEFAULT_ALL命令将该数据写入内部闪存。工厂默认字符串值为3130313031303130h。 MFR_SERIAL (9Eh) MFR_SERIAL命 令为 器 件 装 载 用 于 唯一 识 别 器 件 的 文 本(ISO/IEC8859-1) 字 符， 最 大 字 符 数 为 8。可采 用 STORE_ DEFAULT_ALL命令将该数据写入内部闪存。工厂默认字符串值为3130313031303130h。 38 PMBus 5通道电源管理器 和智能风扇控制器 表 26. MFR_MODE BIT BIT NAME MEANING FORCE_NV_FAULT_LOG Setting this bit to 1 forces the device to log data into the nonvolatile fault log. Once set, the device clears this bit when the action is completed. The host must set again for subsequent action. If an error occurs during this action, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML. 14 CLEAR_NV_FAULT_LOG Setting this bit to 1 forces the device to clear the nonvolatile fault log by writing FFh to all byte locations. Once set, the device clears this bit when the action is completed. The host must set again for subsequent action. If an error occurs during this action, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML. 13 ALERT 15 12 0 11 SOFT_RESET 10:9 PGTIME[1:0] 8 PG_SELECT 7 PSEN_PP_OD 6 PSEN_HI_LO 5:0 0 0 = ALERT disabled (device does not respond to ARA). 1 = ALERT enabled (device responds to ARA and ARA must be used). This bit always returns a 0. This bit must be set, then cleared and set again within 8ms for a soft reset to occur. PGTIME1 PGTIME0 TIME FROM POWER GOOD DETERMINED UNTIL PG OUTPUT IS ASSERTED (ms) 0 0 Immediately 0 1 100 1 0 500 1 1 1000 0 = PG/TACHSEL output is power-good indication. 1 = PG/TACHSEL output is TACHSEL (for dual tachometer fans). For dual tachometer fans, this output is toggled every 500ms. Applies to all PSEN outputs. 0 = PSEN push-pull output. 1 = PSEN open-drain output. Applies to all PSEN outputs. 0 = PSEN active low. 1 = PSEN active high. These bits always return a 0. 注：如果使用双转速计风扇，建议在 TACHSEL=0 时将较低的转速计信号送至 TACH 引脚。 39 MAX34441 MFR_MODE (D1h) MFR_MODE 命令将器件配置为支持厂商规定的命令，关于 MFR_MODE 命令的说明请参考表 26。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 MFR_VOUT_PEAK (D4h) MFR_VOUT_PEAK命令返回最大实测输出电压。利用该命令写数据 0，可以将测量值复位为 0。写入至该命令的任何值都将 被作为将来峰值刷新时的比较值。双数据字节采用 DIRECT格式。 MFR_IOUT_PEAK (D5h) MFR_IOUT_PEAK命令返回最大实测电流。利用该命令写数据 0，可以将测量值复位为 0。写入至该命令的任何值都将被作 为将来峰值刷新时的比较值。双数据字节采用 DIRECT格式。 MFR_TEMPERATURE_PEAK (D6h) MFR_TEMPERATURE_PEAK命令返回最大实测温度。利用该命令写入数据 8000h，可以将测量值复位到最小值。若通过该 命令写入其它任何值，则将其作为将来峰值刷新时的比较值。双数据字节采用 DIRECT格式。 MFR_VOUT_MIN (D7h) MFR_VOUT_MIN 命令返回最小实测输出电压。利用该命令写数据 7FFFh，可将该值复位。写入至该命令的任何值都将被作 为将来最小值更新时的比较值。双数据字节采用 DIRECT格式。 MFR_FAULT_RESPONSE (D9h) MFR_FAULT_RESPONSE 命令规定了器件支持的每种故障条件的响应。在响应故障时，器件总是在相应的状态寄存器中报 告故障，并触发ALERT 输出(若在 MFR_MODE中已使能)。CML 故障不会产生除设置状态位及触发ALERT 输出之外的任何 其它动作。MFR_FAULT_RESPONSE 命令的说明请参见表 27。 表 27. MFR_FAULT_RESPONSE BIT BIT NAME 15 NV_LOG 0 = Do not log the fault into MFR_NV_FAULT_LOG. 1 = Log the fault into MFR_NV_FAULT_LOG. 14 GLOBAL 0 = Affect only the selected page power supply. 1 = Affect all supplies with GLOBAL = 1. 13:12 0 MEANING These bits always return a 0. 11:10 MFR_FAN_FAULT_LIMIT_RESPONSE[1:0] See Table 26. 9:8 IOUT_OC_FAULT_LIMIT_RESPONSE[1:0] See Table 26. 7:6 5:4 OT_FAULT_LIMIT_RESPONSE[1:0] See Table 26 (see Note 1). TON_MAX_FAULT_LIMIT_RESPONSE[1:0] See Table 26. 3:2 VOUT_UV_FAULT_LIMIT_RESPONSE[1:0] See Table 26. 1:0 VOUT_OV_FAULT_LIMIT_RESPONSE[1:0] See Table 26. 注 1：所有使能温度传感器的故障指示进行逻辑“或”后输出。 注 2：温度和风扇故障影响所有使能电源。设置为全局的电源将以相同方式进行响应。该响应是全局通道在特定故障下的最差工作条件响应。未设置 为全局的电源将根据针对特定电源所设置的对温度或风扇故障的响应方式进行响应。 注 3：对电源故障条件的响应由针对故障通道编程的故障响应方式决定。如果该通道是全局的一部分，该故障响应则适用于所有全局通道。 40 PMBus 5通道电源管理器 和智能风扇控制器 RESPONSE [1:0] 11 FAULT RESPONSE • • • Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. Continue power-supply operation. • Shut down the power supply by deasserting the PSEN output. Wait for the time configured in MFR_FAULT_RETRY and restart the supply. If GLOBAL = 1, all enabled power supplies with GLOBAL = 1 are shut down in sequence as configured with TOFF_DELAY, or they are all shut down immediately as configured by bit 0 in ON_OFF_CONFIG. Wait for the time configured in MFR_FAULT_RETRY and restart supplies in sequence as configured with TON_DELAY. If GLOBAL = 1, assert the FAULT output until faults on all GLOBAL supplies clear and MFR_FAULT_RETRY expires. Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. 10 • • • • 01 00 • • • Latch-off the power supply by deasserting the PSEN output. If GLOBAL = 1, all enabled power supplies with GLOBAL = 1 are either shut down in sequence as configured with TOFF_DELAY, or they are all shut down immediately as configured by bit 0 in ON_OFF_CONFIG. Assert the FAULT output if GLOBAL = 1 until power supplies are restarted by the user. Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. • • Set the corresponding fault bit in the appropriate status register. Continue power-supply operation. 注：新状态位置位时，如果 ALERT使能，则触发产生报警。发生特定故障或报警时，第一时间锁存状态位。 MFR_FAULT_RETRY (DAh) MFR_FAULT_RETRY命令设置电源从故障关断到电源重启之间的延迟时间。该命令按照1ms 的整数倍设置重试时间。该命 令适用于所有需要延迟重试的故障响应。如果顺序关断全局电源，在最后一个全局通道关闭之前不会开启重试延时。双数据 字节采用 DIRECT格式，当 MFR_FAULT_RETRY=0000h 时，器件在下一个有效周期重启电源。 MFR_NV_FAULT_LOG (DCh) 每次执行 MFR_NV_FAULT_LOG 命令时，器件返回 255 个字节的数据块，其中包括15 条非易失故障记录之一。必须执行15 次 MFR_NV_FAULT_LOG 命令，才能完全清除非易失故障记录。如果返回的故障记录全部为 FF，说明器件没有写入故障记 录。器件正在工作时，将读取电压、电流、温度和风扇转速的最新工作状态，并更新状态寄存器。所有这些信息被存储在板载 RAM 中。检测到故障时 (若在 MFR_FAULT_RESPONSE中已使能)，器件自动将该信息记录至15 条非易失故障记录之一。写 入15 条故障后，STATUS_CML 的第 0 位置位，主器件必须通过置位 MFR_MODE中的 CLEAR_NV_FAULT_LOG 位清除故 障记录，才能记录其它故障。记录所有最新的状态信息，以及最后 800ms 内(增量为100ms) 的 8 个电压读数和最后 800ms 内的 4 个电流读数。如果电源未被使能测量电流或电压，或者如果温度传感器被禁用，对应的故障记录位置返回 0000h。 每条故障记录的开头有一个 FAULT_LOG_COUNT(16 位计数器)，它指示哪条故障记录最新。该计数器在记录故障超过 65,535 时将重复循环计数。MFR_MODE中的 CLEAR_NV_FAULT_LOG 没有置位时，不清除该计数器。关于 MFR_NV_ FAULT_LOG 命令返回的 255 个字节，请参考表 29 的说明。 41 MAX34441 表 28. MFR_FAULT_RESPONSE编码 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 EACH FAULT IS WRITTEN INTO THE NEXT FAULT LOG FLASH EACH COMMAND READ ACCESSES THE NEXT FAULT LOG FAULT LOG INDEX 0 (255 BYTES) RAM FAULT LOG INDEX 1 (255 BYTES) STATUS VOLTAGE CURRENT TEMPERATURE FAN SPEED FAULT OCCURENCE MFR_NV_FAULT_LOG FAULT LOG INDEX 2 (255 BYTES) FAULT LOG INDEX 14 (255 BYTES) 图5.MFR_NV_FAULT_LOG 如果在器件尝试写入或清除 NV_FAULT_LOG 时发生故障，器件将 STATUS_BYTE 和 STATUS_WORD 中的 CML位置位；不 会置位 STATUS_CML中的任何位，ALERT触发报警 (若在 MFR_MODE中已使能)，参见图 5。 用户提示：VDD 必须高于 2.9V ，器件才能清除或记录数据至 MFR_NV_FAULT_LOG。 表 29. MFR_NV_FAULT_LOG BYTE 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 PARAMETER 00h/FAULT_LOG_INDEX FAULT_LOG_COUNT MFR_TIME_COUNT (LSW) MFR_TIME_COUNT (MSW) STATUS_BYTE/STATUS_CML STATUS_WORD STATUS_VOUT Pages 0/1 STATUS_VOUT Pages 2/3 STATUS_VOUT Page 4/00h STATUS_MFR_SPECIFIC Pages 0/1 STATUS_MFR_SPECIFIC Pages 2/3 STATUS_MFR_SPECIFIC Pages 4/00h STATUS_MFR_SPECIFIC Pages 6/7 STATUS_MFR_SPECIFIC Pages 8/9 STATUS_MFR_SPECIFIC Pages 10/11 RESERVED (0000h) STATUS_FANS_1_2/00h MFR_VOUT_PEAK Page 0 MFR_VOUT_PEAK Page 1 MFR_VOUT_PEAK Page 2 MFR_VOUT_PEAK Page 3 BYTE 128 130 132 134 136 138 140 142 144 146 148 150 152 154 156 158 160 162 164 166 168 PARAMETER READ_VOUT Index = 3, Page 2 READ_VOUT Index = 3, Page 3 READ_VOUT Index = 3, Page 4 RESERVED (0000h) READ_VOUT Index = 4, Page 0 READ_VOUT Index = 4, Page 1 READ_VOUT Index = 4, Page 2 READ_VOUT Index = 4, Page 3 READ_VOUT Index = 4, Page 4 RESERVED (0000h) READ_VOUT Index = 5, Page 0 READ_VOUT Index = 5, Page 1 READ_VOUT Index = 5, Page 2 READ_VOUT Index = 5, Page 3 READ_VOUT Index = 5, Page 4 RESERVED (0000h) READ_VOUT Index = 6, Page 0 READ_VOUT Index = 6, Page 1 READ_VOUT Index = 6, Page 2 READ_VOUT Index = 6, Page 3 READ_VOUT Index = 6, Page 4 PMBus 5通道电源管理器 和智能风扇控制器 BYTE 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 104 106 108 110 112 114 116 118 120 122 124 126 PARAMETER MFR_VOUT_PEAK Page 4 RESERVED (0000h) MFR_IOUT_PEAK Page 0 MFR_IOUT_PEAK Page 1 MFR_IOUT_PEAK Page 2 MFR_IOUT_PEAK Page 3 MFR_IOUT_PEAK Page 4 RESERVED (0000h) MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_VOUT_MIN Page 0 MFR_VOUT_MIN Page 1 MFR_VOUT_MIN Page 2 MFR_VOUT_MIN Page 3 MFR_VOUT_MIN Page 4 RESERVED (0000h) RESERVED (0000h) RESERVED (0000h) VOLTAGE_INDEX/00h READ_VOUT Index = 0, Page 0 READ_VOUT Index = 0, Page 1 READ_VOUT Index = 0, Page 2 READ_VOUT Index = 0, Page 3 READ_VOUT Index = 0, Page 4 RESERVED (0000h) READ_VOUT Index = 1, Page 0 READ_VOUT Index = 1, Page 1 READ_VOUT Index = 1, Page 2 READ_VOUT Index = 1, Page 3 READ_VOUT Index = 1, Page 4 RESERVED (0000h) READ_VOUT Index = 2, Page 0 READ_VOUT Index = 2, Page 1 READ_VOUT Index = 2, Page 2 READ_VOUT Index = 2, Page 3 READ_VOUT Index = 2, Page 4 RESERVED (0000h) READ_VOUT Index = 3, Page 0 READ_VOUT Index = 3, Page 1 6 7 8 9 10 11 BYTE 170 172 174 176 178 180 182 184 186 188 190 192 194 196 198 200 202 204 206 208 210 212 214 216 218 220 222 224 226 228 230 232 234 236 238 240 242 244 246 248 250 252 254 MAX34441 表 29. MFR_NV_FAULT_LOG (续) PARAMETER RESERVED (0000h) READ_VOUT Index = 7, Page 0 READ_VOUT Index = 7, Page 1 READ_VOUT Index = 7, Page 2 READ_VOUT Index = 7, Page 3 READ_VOUT Index = 7, Page 4 RESERVED (0000h) RESERVED (0000h) CURRENT_INDEX/00h READ_IOUT Index = 0, Page 0 READ_IOUT Index = 0, Page 1 READ_IOUT Index = 0, Page 2 READ_IOUT Index = 0, Page 3 READ_IOUT Index = 0, Page 4 RESERVED (0000h) READ_IOUT Index = 1, Page 0 READ_IOUT Index = 1, Page 1 READ_IOUT Index = 1, Page 2 READ_IOUT Index = 1, Page 3 READ_IOUT Index = 1, Page 4 RESERVED (0000h) READ_IOUT Index = 2, Page 0 READ_IOUT Index = 2, Page 1 READ_IOUT Index = 2, Page 2 READ_IOUT Index = 2, Page 3 READ_IOUT Index = 2, Page 4 RESERVED (0000h) READ_IOUT Index = 3, Page 0 READ_IOUT Index = 3, Page 1 READ_IOUT Index = 3, Page 2 READ_IOUT Index = 3, Page 3 READ_IOUT Index = 3, Page 4 RESERVED (0000h) RESERVED (0000h) READ_TEMPERATURE_1 Page 6 READ_TEMPERATURE_1 Page 7 READ_TEMPERATURE_1 Page 8 READ_TEMPERATURE_1 Page 9 READ_TEMPERATURE_1 Page 10 READ_TEMPERATURE_1 Page 11 READ_FAN_SPEED_1 MFR_READ_FAN_PWM LOG_VALID (see note) 注：如果故障记录包含有效数据，LOG_VALID 被设为 DDh。 43 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 MFR_TIME_COUNT (DDh) MFR_TIME_COUNT命令返回自器件上次上电、触发 RST或发生软复位后的器件工作时间，以秒为单位。该计数器为32位值， 用户不能复位。 MFR_MARGIN_CONFIG (E0h) MFR_MARGIN_CONFIG 命令配置数字 PWM 输出，调节电源裕量。MFR_MARGIN_CONFIG 命令的说明请参见表30。 采用 PWM 输出实现电源裕量调节，PWM 频率为 62.5kHz。器件通过闭环控制占空比调节电源裕量。器件具有 6 位的占空比分 辨率。 当 OPERATION 设置为裕量调节状态之一时，器件将调节电源裕量。只有当所有使能电源的电压超出所设置的 POWER_ GOOD_ON 电压时，才会开始调节电源裕量。调节裕量时，使能 PWM 输出，并从 MFR_MARGIN_CONFIG 加载种子值， 作为初始 PWM占空比。器件随后对 8 个VOUT 采样值进行平均，总计时间为 40ms。如果实测 VOUT 和目标值(由VOUT_ MARGIN_HIGH 或VOUT_MARGIN_LOW 设置 )之差大于1%，则对 PWM占空比调整一级步进。占空比调节方向由 MFR_ MARGIN_CONFIG 中的 SLOPE 位决定。对 PWM 的所有更改都发生在对40ms周期内 8 个VOUT 采样值取平均之后。 当 PWM占空比达到 0% 或100%，并且仍未达到目标电压时，器件则不能将电源裕量成功调节到目标值。如果发生这种情况， 器件将继续尝试调节电源裕量，并采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 和 MFR 位置位。 3) 将 STATUS_MFR_SPECIFIC 中的 MARGIN_FAULT位置位。 4) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 PWM 最初采用种子值使能后，也将平均后的 VOUT与目标值进行比较。如果所设置的种子值导致 VOUT超过目标值，则触发 MARGIN_FAULT。例如，如果目标为VOUT_MARGIN_LOW，而 VOUT在使用种子之后低于VOUT_MARGIN_LOW，则 置位 MARGIN_FAULT。响应该故障时，器件继续尝试调节电源余量，并采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 和 MFR 位置位。 3) 将 STATUS_MFR_SPECIFIC 中的 MARGIN_FAULT位置位。 4) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 表30. MFR_MARGIN_CONFIG BIT 44 BIT NAME 15 SLOPE 14:6 0 5:0 SEED MEANING PWM duty cycle to resulting voltage relationship. 0 = Negative slope (increasing duty cycle results in a lower voltage). 1 = Positive slope (increasing duty cycle results in a higher voltage). These bits always return a 0. This 6-bit value is used as the initial PWM duty cycle (i.e., seed value) when the device begins to margin a power supply either up or down. PMBus 5通道电源管理器 和智能风扇控制器 表31. MFR_TEMP_SENSOR_CONFIG BIT 15 BIT NAME ENABLE MEANING 0 = Temperature sensor disabled. 1 = Temperature sensor enabled. The OFFSET setting is used to allow the temperature reading to be normalized among multiple temperature sensors. Values from 00h to 1Eh select the offset value. The valid range is 0NC to +30NC in 1NC steps. If OFFSET is 1Fh, the device automatically uses the value written to the OT_WARN_LIMIT command code for the LUT instead of the digitized measured temperature. OFFSET VALUE 14:10 OFFSET 9:1 0 0 FAN CONFIGURATION 00h Offset = 0NC 01h Offset = +1NC 02h Offset = +2NC 1Dh Offset = +29NC 1Eh Offset = +30NC 1Fh Test Mode These bits always return a 0. 0 = Temperature sensor is not used to control fan speed. 1 = Temperature sensor is used to control fan speed. 45 MAX34441 MFR_TEMP_SENSOR_CONFIG (F0h) MFR_TEMP_SENSOR_CONFIG 命令用于配置温度传感器。表31中介绍了MFR_TEMP_SENSOR_CONFIG 命令。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 MFR_FAN_CONFIG (F1h) MFR_FAN_CONFIG 命 令与 FAN_CONFIG_1_2 配 合， 用 于 配 置 风 扇。关 于 该命 令 的 更 多详 细 信 息， 请 参见 FAN_ CONFIG_1_2 说明，表32介绍了MFR_FAN_CONFIG 命令。 表32. MFR_FAN_CONFIG BIT BIT NAME MEANING The FREQ bits set the PWM frequency. Note: The device does not support pulse stretching. 15:13 12 FREQ[2:0] 0 FREQ2 FREQ1 FREQ0 PWM FREQUENCY 0 0 0 30Hz 0 0 1 50Hz 0 1 0 100Hz 0 1 1 150Hz 1 0 0 Reserved 1 0 1 Reserved 1 1 0 Reserved 1 1 1 25kHz This bit always returns a 0. The HYS bits determine the amount of hysteresis the device uses to determine how far the temperature must fall below the temperature level threshold programmed in the LUT before switching to the lower PWM/RPM value. The hysteresis should be set lower than the minimum difference between two adjacent temperature steps. These bits are ignored if automatic fan control is disabled. 11:10 9 8 46 HYS[1:0] TSFO TACHO HSY1 HSY0 THERMAL HYSTERESIS (NC) 0 0 2 0 1 4 1 0 6 1 1 8 0 = Ramp to 100% PWM duty cycle if temp sensor faults (automatic fan mode) or if no FAN_COMMAND_1 update occurs (manual fan mode) in any 10s period. 1 = Temp sensor fault or update rate to FAN_COMMAND_1 is ignored. Operate at the last updated PWM/RPM value. Note 1: A temp sensor fault is a faulty temperature sensor reading, not an overtemperature fault. Note 2: In automatic fan mode, if the TSFO bit is set to 1, the device ignores a sensor fault and uses the remaining assigned temperature sensors (if any) to control the fan PWM duty cycle; or, if the fan has no available temperature sensors to use, it maintains the last updated PWM/RPM fan value before the fault occurred. 0 = Ramp fan to 100% PWM duty cycle if fan fault is detected. 1 = Do not ramp fan to 100% PWM duty cycle if fan fault is detected. Note: If the fan fault is removed after ramping the PWM to 100% duty cycle, normal fan operation is resumed. PMBus 5通道电源管理器 和智能风扇控制器 BIT BIT NAME MEANING The RAMP bits select how fast the device ramps the PWM from one duty cycle to another (either up or down). In PWM mode, the following table always applies. In RPM mode, the fan speed is read either every 200ms or 1000ms and when the reported fan speed is within 20% of the target speed, the maximum allowed PWM duty cycle change is set to 1%. In RPM mode, the PWM duty cycle is not changed as long as the fan is within Q5% of the target speed. RAMP2 7:5 4 3 RAMP[2:0] 0 ROTOR_HI_LO RAMP1 RAMP0 PWM DUTY_ CYCLE UPDATE RATE (ms) TIME TO RAMP MAX PWM DUTY_ FROM 40% TO CYCLE CHANGE 100% PWM DUTY ALLOWED (%) CYCLE (seconds) 0 0 0 1000 1 60 0 0 1 1000 2 30 0 1 0 1000 3 20 0 1 1 200 1 12 1 0 0 200 2 6 1 0 1 200 3 4 1 1 0 200 4 3 1 1 1 200 5 2.4 This bit always returns a 0. Determines if a locked rotor indication is active low or active high. This bit is ignored if ROTOR = 0. 0 = ROTOR is active low (TACH input is low if the rotor stops). 1 = ROTOR is active high (TACH input is high if the rotor stops). The ROTOR bit selects if the fan does not have a tachometer but rather a stalled (or locked) rotor output. 2 1:0 ROTOR SPIN[1:0] ROTOR FAN OUTPUT 0 Tachometer 1 Stalled/locked rotor detect MAX34441 CONFIGURATION TACH input expects fan RPM TACH input expects locked rotor signal. The polarity is selected with the ROTOR_HI_LO bit (also set MFR_FAN_FAULT_LIMIT = 0001h). The SPIN bits determine how the device spins up (or starts) the fan from a dead stop. To overcome the initial mechanical fan inertia, the device can be programmed to drive the fan at 100% duty cycle until a programmable number of fan revolutions (cumulative count) is detected or a locked rotor signal is negated. The device allows a 2s startup period during which the fan speed monitors are disabled. If after 2s the fan does not respond, the PWM output remains at 100% duty cycle (if TACHO = 0) or goes to 0% duty cycle (if TACHO = 1). SPIN1 SPIN0 0 0 Automatic spin-up disabled SPIN-UP RELAXATION CRITERIA 0 1 Two revolutions or locked rotor negated 1 0 Four revolutions or locked rotor negated 1 1 Eight revolutions or locked rotor negated 注：建议在改变 MFR_FAN_CONFIG 之前禁用风扇。 47 MAX34441 表32. MFR_FAN_CONFIG (续) MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 MFR_FAN_LUT (F2h) MFR_FAN_LUT命令用于配置控制风扇的 LUT。风扇有一个 LUT，它将 8 个可编程温度值映射到 8 个可编程风扇 PWM占空比 (FAN_CONFIG_1_2 中的第 6 位为 0)或 8 个可编程目标风扇转速(FAN_CONFIG_1_2 中的第 6 位为1)，可通过 LUT使用各种 功能。 用户提示：MFR_FAN_LUT 的可编程配置必须是单调的。 表33. MFR_FAN_LUT BYTE NUMBER WORD NAME 0-1 TEMP STEP 0 Temperature for step 0. MEANING 2-3 SPEED STEP 0 Fan PWM duty cycle or fan speed for step 0. 4-5 TEMP STEP 1 Temperature for step 1. 6-7 SPEED STEP 1 Fan PWM duty cycle or fan speed for step 1. 8-9 TEMP STEP 2 Temperature for step 2. 10-11 SPEED STEP 2 Fan PWM duty cycle or fan speed for step 2. 12-13 TEMP STEP 3 Temperature for step 3. 14-15 SPEED STEP 3 Fan PWM duty cycle or fan speed for step 3. 16-17 TEMP STEP 4 Temperature for step 4. 18-19 SPEED STEP 4 Fan PWM duty cycle or fan speed for step 4. 20-21 TEMP STEP 5 Temperature for step 5. 22-23 SPEED STEP 5 Fan PWM duty cycle or fan speed for step 5. 24-25 TEMP STEP 6 Temperature for step 6. 26-27 SPEED STEP 6 Fan PWM duty cycle or fan speed for step 6. 28-29 TEMP STEP 7 Temperature for step 7. 30-31 SPEED STEP 7 Fan PWM duty cycle or fan speed for step 7. TEMPERATURE STEP：温度值设置 TEMPERATURESTEP以摄氏度为单位设置温度，表示器件更新风扇 PWM占空比设置时对应的门限水平。双数据字节采用 DIRECT格式，有效温度范围取决于温度传感器。 表34. 有效温度范围 TEMPERATURE SENSOR VALID RANGE Page 6: Internal Temp Sensor -40NC to +85NC Pages 7 to 10: I2C Remote Temp Sensor -55NC to +125NC Page 11: Remote Thermal Diode Temp Sensor -40NC to +120NC 48 PMBus 5通道电源管理器 和智能风扇控制器 如果 FAN_CONFIG_1_2 中的第 6 位置1，FANSPEEDSTEP 设置每个温度段断点的风扇目标转速 (单位为 RPM)。有效风扇 转速范围为 0至 32,767(含)。 THERMAL HYSTERESIS MAXIMUM DESIRED FAN DUTY CYCLE OR SPEED S7 S6 S5 S4 FAN PWM DUTY CYCLE OR FAN SPEED (IN RPM) S3 S2 S1 S0 PWM = 0% DUTY CYCLE T0 T1 T2 T3 T4 T5 T6 T7 NORMALIZED TEMPERATURE (FROM ONE OR MORE TEMP SENSORS) 图 6. 风扇查找表(LUT) 格式 49 MAX34441 FAN SPEED STEP：风扇PWM占空比或风扇转速设置 如果 FAN_CONFIG_1_2 中的第 6 位置 0，FANSPEEDSTEP 设置每个温度段断点的风扇 PWM占空比。有效占空比范围为 0 至100(含)。大于100(十进制 ) 的任何值产生的 PWM 占空比均为100% ，小于 0(十进制 ) 的任何值产生的 PWM 占空比均 为 0%。 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 MFR_READ_FAN_PWM (F3h) MFR_READ_FAN_PWM 命令返回最新的风扇 PWM占空比实时数值，单位为 %。只要更新 PWM占空比，就更新 MFR_ READ_FAN_PWM，由 MFR_FAN_CONFIG 中的 RATE 位决定。双数据字节采用 DIRECT格式。 MFR_FAN_FAULT_LIMIT (F5h) MFR_FAN_FAULT_LIMIT命令设置触发风扇故障对应的风扇转速值(单位为 RPM)或目标风扇转速的百分比。风扇在该门限 下连续工作超过10s 将触发故障。风扇工作于 RPM 模式时，10s 检查周期开始于器件完成风扇转速 PWM 调节之后。 器件可测量的风扇最慢转速计信号为 60RPM。在双转速计应用中，最慢 RPM 为 360。低于这些最小值的转速计信号被报告 为 0RPM。故障和报警门限应设为大于这些最小 RPM 限制的 RPM 值。 双数据字节采用 DIRECT格式。设为 0000h 时，禁用门限检查 ；设为 0001h 时，则只在锁定转速计输入达到10s 以上时产生 报警输出(当风扇只有转子锁定输出时，应采用该模式)。如果超过 MFR_FAN_FAULT_LIMIT 或检测到转子停转或锁定，器 件采取以下动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 和 FANS 位置位。 3) 将 STATUS_FANS_1_2 中的 FAN_1_FAULT位置位。 4) 根据 MFR_FAULT_RESPONSE中的设置进行响应。 5) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 用户提示：为保证风扇正常工作，必须配置 MFR_FAN_FAULT_LIMIT。 MFR_FAN_WARN_LIMIT (F6h) MFR_FAN_WARN_LIMIT命令设置触发风扇转速报警对应的风扇转速值(单位为 RPM)或目标风扇转速的百分比。风扇在该 门限下连续工作超过10s 将触发报警。风扇工作于 RPM 模式时，10s 检查周期开始于器件完成风扇转速 PWM 调节之后。 通常，MFR_FAN_WARN_LIMIT 设置在 MFR_FAN_FAULT_LIMIT以上。双数据字节采用 DIRECT 格式。设为 0000h 时， 禁用门限检查；设为 0001h 时，则在使用转子锁定风扇时产生报警。超过 MFR_FAN_WARN_LIMIT 时，器件将采取以下 动作： 1) 将 STATUS_BYTE中的 NONEOFTHEABOVE 位置位。 2) 将 STATUS_WORD 中的 NONEOFTHEABOVE 位置位。 3) 将 STATUS_FANS_1_2 中的 FAN_1_WARN 位置位。 4) 通过触发ALERT报警 (若在 MFR_MODE中已使能) 通知主器件。 表35. 监测风扇故障和报警参数 FAN CONTROL MODE 50 LIMIT PARAMETER COMPARISON INTERVAL Manual PWM Fan speed (in RPM) Checked once a second Manual RPM Percentage of programmed target fan speed Checked once a second Automatic PWM Fan speed (in RPM) Checked once a second Automatic RPM Percentage of LUT target fan speed Checked once a second PMBus 5通道电源管理器 和智能风扇控制器 应用信息 电源去耦 使用器件时，为获得最佳结果，可利用一个 0.1µ F电容对 VDD 电源去耦。可能的话，尽量采用高品质表贴陶瓷电容。 表贴元件的引线电感最小，从而改善性能，并且陶瓷电容能 够为去耦提供足够的高频响应。 用1µ F 和10nF电容对 REG25 和 REG18 稳压器输出去耦 (每 路输出放置一组去耦)。 开漏引脚 MSDA、 MSCL、 SCL、 SDA、 FAULT 和 ALERT为开漏 引脚，需要通过外部上拉电阻连接至 V DD，以实现逻辑高 电平。 PSEN0至 PSEN4可由用户配置为 CMOS 推挽式或开漏输出。 配置为开漏时，需要通过外部上拉电阻连接至 VDD，以实 现逻辑高电平 (参见 MFR_MODE 设置 )。 51 MAX34441 MAX34441 PMBus 5通道电源管理器 和智能风扇控制器 典型工作电路 INPUT VOLTAGE IN OUT POWER SUPPLY MAX9938 CURRENT-SENSE AMPLIFIER TRIM EN UP TO 4 CHANNELS MSCL +3.3V VSS SDA SCL OPTIONAL SUPPORT FOR CURRENT MONITORING FROM MUXSEL PSEN1 PWM1 RS-1 RS+1 VDD HOST INTERFACE SPDT MUX 5 CHANNELS PSEN0 PWM0 RS-0 RS+0 MSDA DS75LV I2C TEMP SENSOR LOAD MAX34441 RST ALERT FAULT A0/MUXSEL A1/PG/TACHSEL PSEN2 PWM2 RS-2 RS+2 PSEN3 PWM3 RS-3 RS+3 PSEN4 PWM4 RS-4 RS+4 REG25 RS+5 REG18 RS-5 PWM5 TACH5 REMOTE TEMPERATURE DIODE OPTIONAL SUPPORT FOR DUAL FANS SPDT MUX FROM TACHSEL 封装信息 如需最近的封装外形信息和焊盘布局，请查询china.maxim-ic.com/packages。请注意，封装编码中的“+”、 “#”或“-”仅表示 RoHS 状态。 封装图中可能包含不同的尾缀字符，但封装图只与封装有关，与 RoHS 状态无关。 52 封装类型 封装编码 外形编号 焊盘布局编号 40 TQFN-EP T4066+2 21-0141 90-0053 PMBus 5通道电源管理器 和智能风扇控制器 修订号 修订日期 0 8/10 说明 修改页 最初版本。 — Maxim北京办事处 北京8328信箱 邮政编码 100083 免费电话：800 810 0310 电话：010-6211 5199 传真：010-6211 5299 Maxim 不对 Maxim 产品以外的任何电路使用负责，也不提供其专利许可。Maxim 保留在任何时间、没有任何通报的前提下修改产品资料和规格的权利。 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ©2010MaximIntegratedProducts 53 Maxim 是 MaximIntegratedProducts,Inc.的注册商标。 MAX34441 修订历史 19-5488; Rev 1; 1/12 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller The MAX34441 is a complex system monitor that can manage up to five power supplies and a fan. The power-supply manager monitors the power-supply output voltage and constantly checks for user-programmable overvoltage and undervoltage thresholds. It can also margin the powersupply output voltage up or down to a user-programmable level. The margining is performed in a closed-loop arrangement whereby the device automatically adjusts a pulse-width-modulated (PWM) output and then measures the resultant output voltage. The power-supply manager can also sequence the supplies in any order at both power-up and power-down. With the addition of an external current-sense amplifier, the device can also monitor currents. The device also contains closed-loop fan-speed control. Based on user-programmable settings for fan-control PWM duty cycles or RPM speeds at particular temperature breakpoints, the device automatically adjusts the fan speed in a manner to reduce audible noise and power consumption. Applications Network Switches/Routers Base Stations Servers Features S5 Channels of Power-Supply Management Voltage Measurement/Monitoring_ Differential 12-Bit 1% Accurate ADC Min/Max Threshold Excursion Detection_ Supports Current Monitoring with External_ Current-Sense Amplifier_ Automatic Closed-Loop Margining Programmable Up and Down Sequencing_ Power-Good Output S1 Channel of Fan Control Supports 3-Wire and 4-Wire Fans_ Automatic Closed-Loop Fan-Speed Control_ Support for Dual Tachometer Fans_ Fan-Fault Detection SSupports Up to Six Temperature Sensors External Thermal Diode Interface with_ Automatic Series Resistance Cancellation_ One Internal Temperature Sensor_ Support for Up to Four Additional I2C Digital Temp Sensor ICs_ Fault Detection on All Temp Sensors SPMBus™-Compliant Command Interface SI2C/SMBus-Compatible Serial Bus with Bus Timeout Function Smart Grid Network Systems SOn-Board Nonvolatile Fault Logging and Default Configuration Setting Industrial Controls SNo External Clocking Required S+3.3V Supply Voltage Ordering Information TEMP RANGE PIN-PACKAGE MAX34441ETL+ PART -40NC to +85NC 40 TQFN-EP* MAX34441ETL+T -40NC to +85NC 40 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad. PMBus is a trademark of SMIF, Inc. Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, go to: www.maxim-ic.com/errata. ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX34441 General Description MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller TABLE OF CONTENTS Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Electrical Specifications: I2C/SMBus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 I2C/SMBus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Multiple Device Connection Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Detailed Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Address Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 SMBus/PMBus Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 SMBus/PMBus Communication Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Group Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Group Command Write Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 ALERT and Alert Response Address (ARA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Alert Response Address (ARA) Byte Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Sends or Reads Too Few Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Sends or Reads Too Few Bytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Sends Too Many Bytes or Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Reads Too Many Bytes or Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Sends Improperly Set Read Bit in the Slave Address Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Unsupported Command Code Received . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Invalid Data Received . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Reads from a Write-Only Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Host Writes to a Read-Only Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 SMBus Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 PMBus Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 PMBus Protocol Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Interpreting Received DIRECT Format Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Sending a DIRECT Format Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Fault Management and Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 System Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Temperature Sensor Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Fan Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Dual Fan Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Automatic Fan Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Pulse Stretching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Fan Spin-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 PMBus Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 PAGE (00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 OPERATION (01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 ON_OFF_CONFIG (02h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 CLEAR_FAULTS (03h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 WRITE_PROTECT (10h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 STORE_DEFAULT_ALL (11h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 RESTORE_DEFAULT_ALL (12h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 CAPABILITY (19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 VOUT_MODE (20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 VOUT_MARGIN_HIGH (25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 VOUT_MARGIN_LOW (26h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 VOUT_SCALE_MONITOR (2Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 IOUT_CAL_GAIN (38h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 FAN_CONFIG_1_2 (3Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 FAN_COMMAND_1 (3Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 VOUT_OV_FAULT_LIMIT (40h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 VOUT_OV_WARN_LIMIT (42h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 VOUT_UV_WARN_LIMIT (43h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 VOUT_UV_FAULT_LIMIT (44h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 IOUT_OC_WARN_LIMIT (46h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 IOUT_OC_FAULT_LIMIT (4Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 OT_FAULT_LIMIT (4Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 OT_WARN_LIMIT (51h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 POWER_GOOD_ON (5Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 POWER_GOOD_OFF (5Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 TON_DELAY (60h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 TON_MAX_FAULT_LIMIT (62h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 TOFF_DELAY (64h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 STATUS_BYTE (78h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 STATUS_WORD (79h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 STATUS_VOUT (7Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 STATUS_CML (7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3 MAX34441 TABLE OF CONTENTS (continued) MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller TABLE OF CONTENTS (continued) STATUS_MFR_SPECIFIC (80h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 STATUS_FANS_1_2 (81h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 READ_VOUT (8Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 READ_IOUT (8Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 READ_TEMPERATURE_1 (8Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 READ_FAN_SPEED_1 (90h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 PMBUS_REVISION (98h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 MFR_ID (99h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 MFR_MODEL (9Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 MFR_REVISION (9Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 MFR_LOCATION (9Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 MFR_DATE (9Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 MFR_SERIAL (9Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 MFR_MODE (D1h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 MFR_VOUT_PEAK (D4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 MFR_IOUT_PEAK (D5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 MFR_TEMPERATURE_PEAK (D6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 MFR_VOUT_MIN (D7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 MFR_FAULT_RESPONSE (D9h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 MFR_FAULT_RETRY (DAh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 MFR_NV_FAULT_LOG (DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 MFR_TIME_COUNT (DDh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 MFR_MARGIN_CONFIG (E0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 MFR_TEMP_SENSOR_CONFIG (F0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 MFR_FAN_CONFIG (F1h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 MFR_FAN_LUT (F2h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 TEMPERATURE STEP: Temperature Level Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 FAN SPEED STEP: Fan PWM Duty Cycle or Fan Speed Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 MFR_READ_FAN_PWM (F3h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 MFR_FAN_FAULT_LIMIT (F5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 MFR_FAN_WARN_LIMIT (F6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Power-Supply Decoupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Open-Drain Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Typical Operating Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Figure Figure Figure Figure Figure Figure 1. Automatic Fan Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Fan Speed Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. Fan Spin-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. Power-Supply Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5. MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. Fan Lookup Table (LUT) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 24 25 34 42 49 LIST OF TABLES Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table 1. PMBus Command Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. PMBus/SMBus Serial-Port Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. PMBus Command Code Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. Coefficients for DIRECT Format Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5. Device Parametric Monitoring States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. DS75LV Address Pin Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7. Fan Control Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8. Page Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11. ON_OFF_CONFIG (02h) Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12. WRITE_PROTECT Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13. CAPABILITY Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14. VOUT_SCALE_MONITOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15. FAN_CONFIG_1_2 Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16. PWM Fan Mode (FAN_CONFIG_1_2 Bit 6 = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17. RPM Fan Mode (FAN_CONFIG_1_2 Bit 6 = 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18. IOUT_OC_FAULT_LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19. TON_MAX_FAULT_LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20. STATUS_BYTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21. STATUS_WORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22. STATUS_VOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23. STATUS_CML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24. STATUS_MFR_SPECIFIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25. STATUS_FANS_1_2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26. MFR_MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27. MFR_FAULT_RESPONSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28. MFR_FAULT_RESPONSE Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29. MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30. MFR_MARGIN_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31. MFR_TEMP_SENSOR_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32. MFR_FAN_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33. MFR_FAN_LUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34. Valid Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35. Monitored Fan Fault and Warning Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 16 20 21 21 22 23 26 27 27 28 28 29 30 31 31 31 33 35 35 36 36 36 37 37 39 40 41 42 44 45 46 48 48 50 5 MAX34441 LIST OF FIGURES MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller ABSOLUTE MAXIMUM RATINGS Operating Temperature Range........................... -40NC to +85NC Storage Temperature Range............................. -55NC to +125NC Lead Temperature (soldering, 10s).................................+300NC Soldering Temperature (reflow).......................................+260NC VDD to VSS............................................................-0.3V to +5.5V RS- to VSS.............................................................-0.3V to +0.3V All Other Pins Except REG18 and REG25 Relative to VSS......................... -0.3V to (VDD + 0.3V)* Continuous Power Dissipation (TA = +70NC) TQFN (derate 35.7mW/NC above +70NC)...............2857.1mW *Subject to not exceeding +5.5V. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS (TA = -40NC to +85NC, unless otherwise noted.) PARAMETER SYMBOL MAX UNITS 2.7 5.5 V VIH 0.7 x VDD VDD + 0.3 V VIL 0 0.3 x VDD V VDD Operating Voltage Range VDD Input Logic 1 Input Logic 0 CONDITIONS (Note 1) MIN TYP Input Logic-High: SCL, SDA, MSCL, MSDA VI2C_IH 2.7V P VDD P 3.6V (Note 1) 2.1 VDD + 0.3 V Input Logic-Low: SCL, SDA, MSCL, MSDA VI2C_IL 2.7V P VDD P 3.6V (Note 1) 0 +0.8 V DC ELECTRICAL CHARACTERISTICS (VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.) PARAMETER Supply Current SYMBOL ICPU CONDITIONS Brownout Hysteresis VBOH Monitors VDD (Note 1) Internal System Clock fMOSC Output Logic-Low Output Logic-High PWM, PSEN Pullup Current fERR:MOSC VOL1 VOH1 IPU 2.40 ADC Internal Reference Temperature Drift 6 2.46 2.55 30 mV MHz -3 +2 -6.5 +1.6 VPIN = VSS, VDD = 3.3V 0.4 VDD 0.5 38 % V V 55 107 FA -1 +1 % -0.5 +0.5 % 1.225 VERR V 4.0 -40NC P TA P +25NC IOL = 4mA (Note 1) IOH = -2mA (Note 1) UNITS mA +25NC P TA P +85NC ADC Internal Reference ADC Voltage Measurement Error MAX 8 Monitors VDD (Note 1) System Clock Error (Note 3) TYP 2.5 IPROGRAM VBO Brownout Voltage MIN (Note 2) V PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller (VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS ADC Internal Reference Initial Accuracy (+25NC) TYP -1 ADC Full-Scale Input Voltage VFS ADC Measurement Resolution VLSB 1.213 1.225 MAX UNITS +1 mV 1.237 300 ADC Bit Resolution RS+ Input Resistance RIN INL Internal Temperature Measurement Error 15 MI Q8 LSB LSB Q2 -3 +3 TA = 0NC to +60NC, TDIODE = +60NC to +120NC -1.5 +1.5 TA = 0NC to +60NC, TDIODE = -45NC to +120NC -1.75 +1.75 TA = -40NC to +85NC, TDIODE = +60NC to +120NC -2.75 +2.75 TA = -40NC to +85NC, TDIODE = -45NC to +120NC -3.0 +3.0 TA = -40NC to +85NC Remote Temperature Measurement Error (MAX34441 Error Only) Bits (Note 4) VOFFSET V FV 12 ADC Integral Nonlinearity ADC Offset MIN NC NC Store Default All Time 37 ms Nonvolatile Log Write Time 12 ms Nonvolatile Log Delete Time 200 ms Flash Endurance Data Retention NFLASH TA = +50NC 20,000 TA = +50NC 100 Write Cycles Years Voltage Sample Rate 5 ms Current Sample Rate 200 ms RPM Sample Rate 1000 ms Temperature Sample Rate 1000 ms 12 ms Device Startup Time PWM Frequency PWM Resolution Measured from POR until monitoring begins Power supply Fan 62.5 30 kHz 25,000 Power supply 6 Fan 7 Hz Bits 7 MAX34441 DC ELECTRICAL CHARACTERISTICS (continued) MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller I2C/SMBus INTERFACE ELECTRICAL SPECIFICATIONS (VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 100 kHz SCL Clock Frequency fSCL 10 Bus Free Time Between STOP and START Conditions tBUF 4.7 Fs Hold Time (Repeated) START Condition tHD:STA 4.0 Fs Low Period of SCL tLOW 4.7 Fs High Period of SCL tHIGH 4.0 Fs Receive 0 Transmit 300 Data Hold Time tHD:DAT Data Setup Time tSU:DAT 100 START Setup Time tSU:STA 4.7 SDA and SCL Rise Time ns ns Fs 300 tR SDA and SCL Fall Time 300 tF STOP Setup Time Clock Low Timeout tSU:STO 4.0 tTO 25 ns ns Fs 35 ms Note 1: All voltages are referenced to ground (VSS). Currents entering the IC are specified as positive, and currents exiting the IC are negative. Note 2: This does not include pin input/output currents. Note 3: Guaranteed by design. Note 4: ADC has no missing codes. I2C/SMBus Timing SDA tBUF tF tLOW tHD:STA tSP SCL tHD:STA tHIGH tR tHD:DAT STOP START NOTE: TIMING IS REFERENCED TO VIL(MAX) AND VIH(MIN). 8 tSU:STA tSU:DAT REPEATED START tSU:STO PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller (TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. SUPPLY VOLTAGE SUPPLY CURRENT vs. TEMPERATURE 2.6 2.6 2.5 2.4 IDD (mA) 2.5 IDD (mA) MAX34441 toc02 2.7 MAX34441 toc01 2.7 VDD = 3.3V 2.3 2.4 TA = +25°C 2.3 2.2 2.2 2.1 2.1 2.0 2.0 -40 -20 0 20 40 60 80 2.7 100 3.1 3.5 3.9 4.3 4.7 5.1 5.5 TEMPERATURE (°C) VDD (V) WEAK PULLUP VOLTAGE vs. TIME AT POR (UNLOADED PINS, VDD = 3.3V) IDD vs. TIME DURING A FLASH WRITE (TA = +25°C, VDD = 3.3V) MAX34441 toc04 MAX34441 toc03 C1 = PSEN0 0V C3 = PWM0 0V 1mA/div 1V/div C2 = VDD 0V 0A 2ms/div 1ms/div FILTERED MARGINING VOLTAGE vs. TIME DURING MARGIN UP MAX34441 toc05 200mV/div 0V 100ms/div 9 MAX34441 Typical Operating Characteristics PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller VSS REG18 PSEN3 PWM2 PWM1 PSEN2 PSEN1 PWM0 TOP VIEW REG25 PSEN0 MAX34441 Pin Configuration 30 29 28 27 26 25 24 23 22 21 SDA 31 20 PWM3 SCL 32 19 PSEN4 A0/MUXSEL 33 18 PWM4 FAULT 34 17 TACH5 CONTROL 35 16 PWM5 MAX34441 VSS 36 15 MSCL A1/PG/TACHSEL 37 14 MSDA ALERT 38 RS-5 39 13 RST EP + 12 RS-2 11 RS+2 7 8 9 10 VDD RS-1 6 RS-0 RS+4 5 RS+1 VSS 4 RS+0 3 RS-3 2 RS+3 1 RS-4 RS+5 40 TQFN (6mm × 6mm × 0.75mm) Pin Description 10 PIN NAME FUNCTION 1 RS-4 Ground Reference for ADC4 Voltage Measurement 2, 21, 36 VSS Digital-Supply Return Node (Ground) 3 RS+4 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-4 4 RS-3 Ground Reference for ADC3 Voltage Measurement 5 RS+3 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-3 6 RS+0 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-0 7 RS-0 Ground Reference for ADC0 Voltage Measurement 8 RS+1 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-1 9 VDD Supply Voltage. Bypass VDD to VSS with a 0.1FF capacitor. Ground Reference for ADC1 Voltage Measurement 10 RS-1 11 RS+2 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-2 12 RS-2 Ground Reference for ADC2 Voltage Measurement 13 14 RST MSDA Master I2C Data Input/Output. Open-drain output. 15 MSCL Master I2C Clock Output. Open-drain output. 16 PWM5 Fan PWM Output #5. CMOS push-pull output. Low when the fan is disabled. A 100% duty cycle implies this pin is continuously high. 17 TACH5 Fan Tachometer Input 18 PWM4 PWM Margin Output #4. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. 19 PSEN4 Power-Supply Enable Output #4. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. Reset Active-Low Input PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller PIN NAME FUNCTION 20 PWM3 PWM Margin Output #3. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. 22 REG18 Regulator for Low-Voltage Digital Circuitry. Bypass REG18 to VSS with 1FF and 10nF capacitors. Do not connect other circuitry to this pin. 23 PSEN3 Power-Supply Enable Output #3. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. 24 PWM2 PWM Margin Output #2. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. 25 PSEN2 Power-Supply Enable Output #2. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. 26 PWM1 PWM Margin Output #1. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. 27 PSEN1 Power-Supply Enable Output #1. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. 28 PWM0 PWM Margin Output #0. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. 29 REG25 Regulator for Analog Circuitry. Bypass REG25 to VSS with 1FF and 10nF capacitors. Do not connect other circuitry to this pin. 30 PSEN0 Power-Supply Enable Output #0. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. 31 SDA I2C/SMBus-Compatible Input/Output 32 SCL I2C/SMBus-Compatible Clock Input 33 SMBus Address 0 Input/Multiplexer Control Output. This dual-function pin is sampled on device power-up to determine the SMBus address; connect a 100kI resistor from this pin to either VSS or A0/MUXSEL VDD to set the address. After device power-up, this pin becomes an output that acts as voltage/ current selector for an external analog multiplexer. MUXSEL is low for voltage measurements and high for current measurements. 34 FAULT Active-Low, Open-Drain Fault Input/Output. This pin is asserted when one or more of the power supplies in a global group are shut down due to a fault condition. Also, this pin is monitored and, when it is asserted, all power supplies in a global group are shut down. This pin is used to provide hardware control for power supplies in a global group across multiple devices. This output is unconditionally deasserted when RST is asserted or the device is power cycled. This pin has a 50Fs deglitch filter. 35 CONTROL Device Enable. Option through ON_OFF_CONFIG for active-low or active-high power-supply control. This pin has a 50Fs deglitch filter. A1/PG/ TACHSEL SMBus Address 1 Input/Power-Good Output. This triple-function pin is sampled on device powerup to determine the SMBus address; connect a 100kI resistor from this pin to either VSS or VDD to set the address. After device power-up, this pin becomes an output that transitions high when all the enabled power supplies are above their associated POWER_GOOD_ON thresholds. Alternately, this pin can be programmed through MFR_MODE to select between two tachometers in dual-fan applications. 37 38 Active-Low, Open-Drain Alert Output 39 ALERT RS-5 Thermal Diode ADC Voltage Negative-Sense Input, Measurement Relative to RS+5 40 RS+5 Thermal Diode ADC Voltage Positive-Sense Input, Measurement Relative to RS-5 — EP Exposed Pad (Bottom Side of Package). Connect EP to VSS. Note: All pins except VDD, VSS, REG18, REG25, ADC, and the EP are high impedance with a 50µA pullup during device power-up and reset. After device reset, the weak pullup is removed, and the pin is configured as input or output. 11 MAX34441 Pin Description (continued) PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MAX34441 Block Diagram VDD VSS REG25 VSS REG18 VSS POWER CONTROL PULSEWIDTH MODULATOR 2.5V VREG 1.8V VREG PWM0 PWM1 PWM2 PWM3 PWM4 PWM5 PSEN0 4MHz OSCILLATOR MSCL SDA SCL RST ALERT FAULT CONTROL A0/MUXSEL A1/PG/TACHSEL SMBus MASTER INTERFACE ADC SYSTEM CONTROL SIGNALS MAX34441 12 FAN TACHOMETER INPUT SMBus SLAVE INTERFACE RAM FLASH PSEN1 PSEN2 PSEN3 PSEN4 MUX MSDA 16-BIT MAXQ RISC CORE POWERSUPPLY OUTPUT ENABLES TEMP SENSOR TACH5 RS+0 RS-0 RS+1 RS-1 RS+2 RS-2 RS+3 RS-3 RS+4 RS-4 RS+5 RS-5 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller +3.3V ALERT HOST INTERFACE CLOCK DATA CONTROL RST SDA SCL RST ALERT MAX34441 #0 FAULT CONTROL A1/PG/TACHSEL A0/MUXSEL +3.3V SDA SCL RST ALERT FAULT MAX34441 #1 CONTROL A1/PG/TACHSEL A0/MUXSEL ADDITIONAL DEVICES 13 MAX34441 Multiple Device Connection Diagram MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Detailed Description The MAX34441 is a highly integrated system monitor based upon a 4MHz, 16-bit, MAXQM microcontroller with factory-programmed functionality to monitor up to five power supplies and a system cooling fan. The device provides power-supply closed-loop control, fan-speed monitoring, and local/remote thermal-sensing facilities. The power-supply manager monitors the power-supply output voltage and constantly checks for user-programmable overvoltage and undervoltage thresholds. It also can margin the power-supply output voltage up or down by a user-programmable level. The margining is performed in a closed-loop arrangement, whereby the device automatically adjusts a pulse-width-modulated (PWM) output and then measures the resultant output voltage. The power-supply manager can also sequence the supplies in any order at both power-up and powerdown. With the addition of an external current-sense amplifier, the device can also monitor currents. Thermal monitoring can be accomplished using up to six temperature sensors, including an on-chip thermal sensor, four DS75LV digital thermometers, and a remote thermal diode. Temperature offset can be added to individual sensors to compensate for thermal differences in a system. Communication with the DS75LV temperature sensor is conducted through a dedicated I2C/SMBus interface. The device also contains closed-loop fan-speed control. Based on user-programmable settings for fan-control PWM duty cycles or for fan RPM speeds at particular temperature breakpoints, the device automatically adjusts the fan speed in a manner to reduce audible noise and power consumption. The device provides ALERT and FAULT output signals. Host communications are conducted through a PMBuscompatible communications port. Address input connections are also provided to allow up to four MAX34441 devices to reside on the system’s I/O bus. Table 1. PMBus Command Codes CODE 00h 01h 02h 03h 10h 11h 12h 19h 20h 25h 26h 2Ah 38h 3Ah 3Bh 40h 42h 43h 44h 46h 4Ah 4Fh COMMAND NAME PAGE OPERATION ON_OFF_CONFIG CLEAR_FAULTS WRITE_PROTECT STORE_DEFAULT_ALL RESTORE_DEFAULT_ALL CAPABILITY VOUT_MODE VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_SCALE_MONITOR IOUT_CAL_GAIN FAN_CONFIG_1_2 FAN_COMMAND_1 VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT IOUT_OC_WARN_LIMIT IOUT_OC_FAULT_LIMIT OT_FAULT_LIMIT TYPE PAGE 0–4 R/W Byte R/W Byte R/W Byte Send Byte R/W Byte Send Byte Send Byte Read Byte Read Byte R/W Word R/W Word R/W Word R/W Word R/W Byte R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W R/W R/W W R/W W W R R R/W R/W R/W R/W — — R/W R/W R/W R/W R/W R/W — MAXQ is a registered trademark of Maxim Integrated Products, Inc. 14 PAGE 5 PAGE 6–11 (NOTE R/W — R/W W R/W W W R R — — — — R/W R/W — — — — — — — 1) R/W — R/W W R/W W W R R — — — — — — — — — — — — R/W PAGE 255 R/W W R/W W R/W W W R R — — — — — — — — — — — — — NO. OF BYTES FLASH STORED (NOTE 2) DEFAULT VALUE (NOTE 2) 1 1 1 0 1 0 0 1 1 2 2 2 2 1 2 2 2 2 2 2 2 2 N N Y N N N N N FIXED Y Y Y Y Y Y Y Y Y Y Y Y Y 00h 00h 1Ah — 00h — — 00h/10h 40h 0000h 0000h 7FFFh 0000h 00h FFFFh 7FFFh 7FFFh 0000h 0000h 7FFFh 0000h 7FFFh PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller CODE COMMAND NAME TYPE PAGE 0–4 51h 5Eh 5Fh 60h 62h 64h 78h 79h 7Ah 7Eh 80h 81h 8Bh 8Ch 8Dh 90h 98h 99h 9Ah 9Bh 9Ch 9Dh 9Eh D1h D4h D5h D6h D7h D9h DAh DCh DDh E0h F0h F1h F2h F3h F5h F6h OT_WARN_LIMIT POWER_GOOD_ON POWER_GOOD_OFF TON_DELAY TON_MAX_FAULT_LIMIT TOFF_DELAY STATUS_BYTE STATUS_WORD STATUS_VOUT STATUS_CML STATUS_MFR_SPECIFIC STATUS_FANS_1_2 READ_VOUT READ_IOUT READ_TEMPERATURE_1 READ_FAN_SPEED_1 PMBUS_REVISION MFR_ID MFR_MODEL MFR_REVISION MFR_LOCATION MFR_DATE MFR_SERIAL MFR_MODE MFR_VOUT_PEAK MFR_IOUT_PEAK MFR_TEMPERATURE_PEAK MFR_VOUT_MIN MFR_FAULT_RESPONSE MFR_FAULT_RETRY MFR_NV_FAULT_LOG MFR_TIME_COUNT MFR_MARGIN_CONFIG MFR_TEMP_SENSOR_CONFIG MFR_FAN_CONFIG MFR_FAN_LUT MFR_READ_FAN_PWM MFR_FAN_FAULT_LIMIT MFR_FAN_WARN_LIMIT R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word Read Byte Read Word Read Byte Read Byte Read Byte Read Byte Read Word Read Word Read Word Read Word Read Byte Read Byte Read Byte Read Word Block R/W Block R/W Block R/W R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word Block Read Block Read R/W Word R/W Word R/W Word Block R/W Read Word R/W Word R/W Word — R/W R/W R/W R/W R/W R R R R R — R R — — R R R R R/W R/W R/W R/W R/W R/W — R/W R/W R/W R R R/W — — — — — — PAGE 5 PAGE 6–11 (NOTE — — — — — — R R — R — R — — — R R R R R R/W R/W R/W R/W — — — — — R/W R R — — R/W R/W R R/W R/W 1) R/W — — — — — R R — R R — — — R — R R R R R/W R/W R/W R/W — — R/W — — R/W R R — R/W — — — — — PAGE 255 — — — — — — R R — R — — — — — — R R R R R/W R/W R/W R/W — — — — — R/W R R — — — — — — — NO. OF BYTES FLASH STORED (NOTE 2) DEFAULT VALUE (NOTE 2) 2 2 2 2 2 2 1 2 1 1 1 1 2 2 2 2 1 1 1 2 8 8 8 2 2 2 2 2 2 2 255 4 2 2 2 32 2 2 2 Y Y Y Y Y Y N N N N N N N N N N FIXED FIXED FIXED FIXED Y Y Y Y N N N N Y Y Y N Y Y Y Y N Y Y 7FFFh 0000h 0000h 0000h 0000h 0000h 00h 0000h 00h 00h 00h 00h 0000h 0000h 0000h 0000h 11h 4Dh 52h 3031h (Note 3) (Note 3) (Note 3) 0000h 0000h 0000h 8000h 7FFFh 0000h 0000h (Note 4) (Note 5) 0000h 0000h 0000h (Note 6) 0000h 0000h 0000h Note 1: Common commands are shaded. Access through any page results in the same device response. Note 2: In the Flash Stored column, an “N” indicates that this parameter is not stored in flash memory when the STORE_ DEFAULT_ALL command is executed and the value shown in the Default Value column is automatically loaded upon power-on reset or when the RST pin is asserted. A “Y” in the Flash Stored column indicates that the currently loaded value in this parameter is stored in flash memory when the STORE_DEFAULT_ALL command is executed and is automatically 15 MAX34441 Table 1. PMBus Command Codes (continued) MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 1. PMBus Command Codes (continued) Note Note Note Note 3: 4: 5: 6: loaded upon power-on reset or when the RST pin is asserted and the value shown in the Default Value column is the value when shipped from the factory. “FIXED” in the Flash Stored column means this value is fixed at the factory and cannot be changed. The factory-set default value for this 8-byte block is 3130313031303130h. The factory-set default value for the complete block of the MFR_NV_FAULT_LOG is FFh. The power-on reset value for this 4-byte block is 00000000h. The factory-set default value for the complete block of the MFR_FAN_LUT is 00h. Address Select Table 2. PMBus/SMBus Serial-Port Address A1 7-BIT SLAVE ADDRESS A0 100kI to VSS 100kI to VDD On device power-up, the device samples the A0 and A1 pins to determine the PMBus/SMBus serial-port address. SMBus/PMBus Operation 100kI to VSS 1101 010 (D4h) 100kI to VDD 1101 011 (D6h) 100kI to VSS 1101 100 (D8h) 100kI to VDD 1101 101 (DAh) The device implements the PMBus command structure using the SMBus format. The structure of the data flow between the host and the slave is shown below for several different types of transactions. All transactions begin with a host sending a command code that is immediately preceded with a 7-bit slave address (R/W = 0). Data is sent most significant bit (MSB) first. SMBus/PMBus Communication Examples READ WORD FORMAT 1 7 S SLAVE ADDRESS 1 W 1 8 A COMMAND CODE 1 1 7 A Sr SLAVE ADDRESS 1 1 8 1 8 1 1 R A DATA BYTE LOW A DATA BYTE HIGH NA P READ BYTE FORMAT 1 7 1 1 8 1 1 7 1 1 8 1 1 S SLAVE ADDRESS W A COMMAND CODE A Sr SLAVE ADDRESS R A DATA BYTE NA P 1 8 1 8 A COMMAND CODE A DATA BYTE LOW WRITE WORD FORMAT 1 7 S SLAVE ADDRESS 1 W 1 8 1 1 A DATA BYTE HIGH A P WRITE BYTE FORMAT 1 7 S SLAVE ADDRESS 1 W 1 8 1 8 1 1 A COMMAND CODE A DATA BYTE A P SEND BYTE FORMAT 16 1 7 1 1 8 1 1 S SLAVE ADDRESS W A COMMAND CODE A P KEY: S = START Sr = REPEATED START P = STOP W = WRITE BIT (0) R = READ BIT (1) A = ACKNOWLEDGE (0) NA = NOT ACKNOWLEDGE (1) SHADED BLOCK = SLAVE TRANSACTION PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller continuous data stream. All the devices addressed during this transaction wait for the host to issue a STOP before beginning to respond to the command. Group Command Write Format SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE 1 1 7 S SLAVE ADDRESS 1 W 1 8 A COMMAND CODE 1 8 A DATA BYTE LOW 1 8 1 A DATA BYTE HIGH A UUU SLAVE ADDRESS, COMMAND BYTE, AND DATA BYTE FOR DEVICE 2 1 7 Sr SLAVE ADDRESS 1 W 1 8 1 8 1 A COMMAND CODE A DATA BYTE A UUU KEY: S = START Sr = REPEATED START SLAVE ADDRESS AND SEND BYTE FOR DEVICE 3 1 7 1 1 8 1 Sr SLAVE ADDRESS W A COMMAND CODE A P = STOP W = WRITE BIT (0) UUU A = ACKNOWLEDGE (0) SHADED BLOCK = SLAVE TRANSACTION UUU SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE N 1 7 1 1 8 1 8 1 8 1 1 Sr SLAVE ADDRESS W A COMMAND CODE A DATA BYTE LOW A DATA BYTE HIGH A P Addressing The device responds to receiving its fixed slave address by asserting an acknowledge (ACK) on the bus. The device does not respond to a general call address; it only responds when it receives its fixed slave address. The only exception to this operation is if the ALERT output is enabled (ALERT bit = 1 in MFR_MODE) and ALERT has been asserted. When this condition occurs, the device only recognizes the alert response address (0001 100, 18h). See the ALERT and Alert Response Address (ARA) section for more details. ALERT and Alert Response Address (ARA) If the ALERT output is enabled (ALERT bit = 1 in MFR_MODE), when a fault occurs the device asserts the ALERT signal and then waits for the host to send the alert response address (ARA) as shown in the Alert Response Address (ARA) Byte Format section. While waiting for the ARA, the device does not respond to its fixed slave address. When the ARA is received and the device is asserting ALERT, the device ACKs it and then attempts to place its fixed slave address on the bus by arbitrating the bus, since another device could also try to respond to the ARA. The rules of arbitration state that the lowest address device wins. If the device wins the arbitration, it deasserts ALERT and begins to respond to its fixed slave address. If the device loses arbitration, it keeps ALERT asserted and waits for the host to once again send the ARA. 17 MAX34441 Group Command The device supports the group command. With the group command, a host can write different data to multiple devices on the same serial bus with one long MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Alert Response Address (ARA) Byte Format 1 7 S ARA 0001100 1 R 1 8 1 1 A DEVICE SLAVE ADDRESS WITH LSB = 0 NA P Host Sends or Reads Too Few Bits If for any reason the host does not complete writing a full byte or reading a full byte from the device before a START or STOP is received, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the DATA_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). Host Sends or Reads Too Few Bytes For each supported command, the device expects a fixed number of bytes to be written or read from the device. If for any reason fewer than the expected number of bytes is written to or read from the device, the device completely ignores the command and takes no action. Host Sends Too Many Bytes or Bits For each supported command, the device expects a fixed number of bytes to be written to the device. If for any reason more than the expected number of bytes or bits is written to the device, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the DATA_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). Host Reads Too Many Bytes or Bits For each supported command, the device expects a fixed number of bytes to be read from the device. If for any reason more than the expected number of bytes or bits is read from the device, the device does the following: 1) Sends all ones (FFh) as long as the host keeps acknowledging. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the DATA_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). 18 Host Sends Improperly Set Read Bit in the Slave Address Byte If the device receives the R/W bit in the slave address set to one immediately preceding the command code, the device does the following (note this does not apply to ARA): 1) ACKs the address byte. 2) Sends all ones (FFh) as long as the host keeps acknowledging. 3) Sets the CML bit in STATUS_BYTE. 4) Sets the CML bit in STATUS_WORD. 5) Sets the DATA_FAULT bit in STATUS_CML. 6) Notifies the host through ALERT assertion (if enabled). Unsupported Command Code Received If the host sends the device a command code that it does not support, or if the host sends a command code that is not supported by the current PAGE setting, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the COMM_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). Invalid Data Received The device checks the PAGE, OPERATION, and WRITE_PROTECT command codes for valid data. If the host writes a data value that is invalid, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the DATA_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller 1) ACKs the address byte. 2) Ignores the command. 3) Sends all ones (FFh) as long as the host keeps acknowledging. 4) Sets the CML bit in STATUS_BYTE. 5) Sets the CML bit in STATUS_WORD. 6) Sets the DATA_FAULT bit in STATUS_CML. 7) Notifies the host through ALERT assertion (if enabled). Host Writes to a Read-Only Command When a write request is issued to a read-only command, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the COMM_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). SMBus Timeout If during an active SMBus communication sequence the SCL signal is held low for greater than the timeout duration (nominally 30ms), the device terminates the sequence and resets the serial bus. It takes no other action. No status bits are set. PMBus Operation From a software perspective, the device appears as a PMBus device capable of executing a subset of PMBus commands. A PMBus 1.1-compliant device uses the SMBus version 1.1 for transport protocol and responds to the SMBus slave address. In this data sheet, the term SMBus is used to refer to the electrical characteristics of the PMBus communication using the SMBus physical layer. The term PMBus is used to refer to the PMBus command protocol. The device employs a number of standard SMBus protocols such as Write Word, Read Word, Write Byte, Read Byte, Send Byte, and so on to program output voltage and warning/faults thresholds, read monitored data, and provide access to all manufacturer-specific commands. The device supports the group command. The group command is used to send commands to more than one PMBus device. It is not required that all the devices receive the same command. However, no more than one command can be sent to any one device in one group command packet. The group command must not be used with commands that require receiving devices to respond with data, such as the STATUS_BYTE command. When the device receives a command through this protocol, it immediately begins execution of the received command after detecting the STOP condition. The device supports the PAGE command and uses it to select which individual channel to access. When a data word is transmitted, the lower order byte is sent first and the higher order byte is sent last. Within any byte, the most significant bit (MSB) is sent first and the least significant bit (LSB) is sent last. PMBus Protocol Support The device supports a subset of the commands defined in the PMBus™ Power System Management Protocol Specification Part II - Command Language, Revision 1.1. For detailed specifications and the complete list of PMBus commands, refer to Part II of the PMBus specification available at www.PMBus.org. The supported PMBus commands and the corresponding device behavior are described in this document. All data values are represented in DIRECT format, unless otherwise stated. Whenever the PMBus specification refers to the PMBus device, it is referring to the MAX34441 operating in conjunction with a power supply or fan. While the command can call for turning on or turning off the PMBus device, the MAX34441 always remains on to continue communicating with the PMBus master, and the MAX34441 transfers the command to the power supply accordingly. Data Format Voltage data for commanding or reading the output voltage or related parameters (such as the overvoltage threshold) is presented in DIRECT format. DIRECT format data is a 2-byte, two’s complement binary value. DIRECT format data can be used with any command that sends or reads a parametric value. The DIRECT format uses an equation and defined coefficients to calculate the desired values. Table 3 shows the coefficients used by the device. 19 MAX34441 Host Reads from a Write-Only Command When a read request is issued to a write-only command (CLEAR_FAULTS, STORE_DEFAULT_ALL, RESTORE_DEFAULT_ALL), the device does the following: MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 3. PMBus Command Code Coefficients PARAMETER UNITS RESOLUTION MAX m b R Voltage VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT POWER_GOOD_ON POWER_GOOD_OFF READ_VOUT MFR_VOUT_PEAK MFR_VOUT_MIN mV 1 32,767 1 0 0 Voltage Scaling VOUT_SCALE_MONITOR — 1/32,767 1 32,767 0 0 Current IOUT_OC_WARN_LIMIT IOUT_OC_FAULT_LIMIT READ_IOUT MFR_IOUT_PEAK mA 1 32,767 1 0 0 IOUT_CAL_GAIN mI 0.1 3276.7 1 0 1 OT_FAULT_LIMIT OT_WARN_LIMIT READ_TEMPERATURE_1 MFR_TEMPERATURE_PEAK NC 0.01 327.67 1 0 2 READ_FAN_SPEED_1 FAN_COMMAND_1 MFR_FAN_FAULT_LIMIT MFR_FAN_WARN_LIMIT RPM 1 32,767 1 0 0 FAN_COMMAND_1 MFR_READ_FAN_PWM MFR_FAN_FAULT_LIMIT MFR_FAN_WARN_LIMIT % 0.01 327.67 1 0 2 TON_DELAY TON_MAX_FAULT_LIMIT TOFF_DELAY MFR_FAULT_RETRY ms 1 32,767 1 0 0 Current Scaling Temperature Fan Speed Timing COMMANDS Interpreting Received DIRECT Format Values The host system uses the following equation to convert the value received from the PMBus device—in this case, the MAX34441—into a reading of volts, degrees Celsius, or other units as appropriate: X = (1/m) x (Y x 10-R - b) where X is the calculated, real world value in the appropriate units (V, NC, etc.); m is the slope coefficient; Y is the 2-byte, two’s complement integer received from the PMBus device; b is the offset; and R is the exponent. 20 Sending a DIRECT Format Value To send a value, the host must use the below equation to solve for Y: Y = (mX + b) x 10R where Y is the 2-byte, two’s complement integer to be sent to the unit; m is the slope coefficient; X is the real world value, in units such as volts, to be converted for transmission; b is the offset; and R is the exponent. PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 4. Coefficients for DIRECT Format Value COMMAND CODE COMMAND NAME m b R 25h VOUT_MARGIN_HIGH 1 0 0 8Bh READ_VOUT 1 0 0 The host sends the SMBus ARA (0001 100). The device ACKs the SMBus ARA, transmits its slave address, and deasserts ALERT. The system controller then communicates with PMBus commands to retrieve the fault/warning status information from the device. See the individual command sections for more details. Faults and warnings that are latched in the status registers are cleared when any one of the following conditions occurs: • A CLEAR_FAULTS command is received. • The RST pin is toggled. If a host wants to set the device to change the powersupply output voltage to 3.465V (or 3465mV), the corresponding VOUT_MARGIN_HIGH value is: • Bias power to the device is removed and then reapplied. Y = (1 x 3465 + 0) x 100 = 3465 (decimal) = 0D89h (hex) • The output is commanded through the CONTROL pin, the OPERATION command, to turn off and then turn back on. Conversely, if the host received a value of 0D89h on a READ_VOUT command, this is equivalent to: X = (1/1) x (0D89h x 10-(-0) - 0) = 3465mV = 3.465V Power supplies and power converters generally have no way of knowing how their outputs are connected to ground. Within the power supply, all output voltages are most commonly treated as positive. Accordingly, all output voltages and output voltage-related parameters of PMBus devices are commanded and reported as positive values. It is up to the system to know that a particular output is negative if that is of interest to the system. All output-voltage-related commands use 2 data bytes. Fault Management and Reporting For reporting faults/warnings to the host on a real-time basis, the device asserts the open-drain ALERT pin (if enabled in MFR_MODE) and sets the appropriate bit in the various status registers. On recognition of the ALERT assertion, the host or system manager is expected to poll the I2C bus to determine the device asserting ALERT. One or more latched-off power supplies is only restarted when one of the following occurs: • The RST pin is toggled. • Bias power to the device is removed and then reapplied. A power supply is not allowed to turn on if any faults the supply responds to are detected. Only after the faults clear is the power supply allowed to turn on. When global supplies are being sequenced on, a fault on any of the supplies keeps all supplies from being turned on. A system-wide power-up (OPERATION command is received to turn the supplies on when PAGE is 255 or the CONTROL pin is toggled to turn on the supplies) allows all enabled power supplies to power-up. If any faults are detected once the supplies start to turn on, the response of MFR_FAULT_RESPONSE is performed. The device responds to fault conditions according to the manufacturer fault response command (MFR_FAULT_RESPONSE). This command byte determines how the device should respond to each Table 5. Device Parametric Monitoring States PARAMETER Overvoltage Undervoltage Overcurrent Power-Up Time Overtemperature Fan Speed REQUIRED CONDITIONS FOR ACTIVE MONITORING Power supply enabled (TON_MAX_FAULT_LIMIT ≠ 0000h) ACTION DURING A FAULT Continue monitoring • • • Power supply enabled (TON_MAX_FAULT_LIMIT ≠ 0000h) PSEN output is active Channel’s VOUT must have exceeded VOUT_UV_FAULT during channel power-up Stop monitoring while the power supply is off • • Power supply enabled (TON_MAX_FAULT_LIMIT ≠ 0000h) Current monitoring enabled (IOUT_OC_FAULT_LIMIT ≠ 0000h) Continue monitoring Power supply enabled (TON_MAX_FAULT_LIMIT ≠ 0000h) Temp sensor enabled (ENABLE in MFR_TEMP_SENSOR_CONFIG = 1) Fan enabled (bit 7 in FAN_CONFIG_1_2 = 1) Monitor only during power-on Continue monitoring Continue monitoring 21 MAX34441 The following example demonstrates how the host can send and retrieve values from the device. Table 4 shows the coefficients used in the following parameters. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller particular fault. Table 5 illustrates the required conditions and fault actions for specific parameters. System Watchdog Timer The device uses an internal watchdog timer that is internally reset every 5ms. In the event that the device is locked up and this watchdog reset does not occur after 500ms, the device automatically resets. After the reset occurs, the device reloads all configuration values that were stored to flash and begins normal operation. After the reset, the device also does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the WATCHDOG bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE). Temperature Sensor Operation The device can monitor up to six different temperature sensors. It can monitor up to four remote I2C-based temperature sensors plus a remote diode and its own internal temperature sensor. Each of the enabled temperature sensors is measured once a second. The remote diode and internal temperature sensors are averaged four times to reduce the affect of noise. Each time the device attempts to read a temperature sensor it checks for faults. For the remote diode, a fault is defined as reading greater than +160NC or less than -60NC. For the internal temperature sensor, a fault is defined as reading greater than +130NC or less than -60NC. For the I2C temperature sensors, a fault is defined as a communication access failure. Temperature sensor faults are reported by setting the temperature reading to 7FFFh. A temperature sensor fault results in the setting of the TEMPERATURE bit in STATUS_BYTE and STATUS_WORD and ALERT is asserted (if enabled in MFR_MODE). No bits are set in STATUS_MFR_SPECIFIC. The temperatures do not have to be used to control the fan speed. They can be enabled and used for temperature monitoring only. Reading disabled temperature sensors returns a fixed value of 0000h. The remote diode temperature sensor can support either npn or pnp transistors. The device automatically cancels the series resistance that can affect remote diodes that are located far from the device. The device can control up to four DS75LV digital temperature sensors. The A0, A1, and A2 pins on the DS75LV 22 Table 6. DS75LV Address Pin Configurations DS75LV ADDRESS PIN CONFIGURATION PAGE MAX34441 I2C TEMP SENSOR A2 A1 A0 7 TEMP SENSOR I2C 0 0 0 0 8 TEMP SENSOR I2C 1 0 0 1 9 TEMP SENSOR I2C 2 TEMP SENSOR I2C 3 0 1 0 0 1 1 10 should be configured as shown in Table 6. The thermostat function on the DS75LV is not used and thus the O.S. output should be left open circuit. Fan Control Operation Fan control has four operational modes. The mode is determined by the combination of FAN_COMMAND_1 and bit 6 of FAN_CONFIG_1_2 (see Table 7). Fan control can be disabled by setting bit 7 in FAN_CONFIG_1_2 to zero. Dual Fan Applications In dual fan applications operating in RPM mode, the tachometer selected when TACHSEL = 0 is closeloop-controlled to the target RPM. Once PWM ramping is complete, TACHSEL toggles between the two tachometers every 500ms for monitoring purposes. The slower of the two tachometer signals is reported by READ_FAN_SPEED_1 and is used as a comparison for fan faults and warning. In dual fan applications operating in PWM mode, TACHSEL always switches every 500ms. If one of the two tachometer signals operate at a slower speed, it is recommended that the slower tachometer be presented to the TACH input when TACHSEL = 0. Automatic Fan Control Operation In the automatic mode, the fan is controlled in a closed loop based on the controlling temperature (the highest postnormalized temperature reading) and the associated fan control PWM duty cycle (in %) or fan speed (in RPM). These parameters are assigned in the fan lookup table (LUT). See the MFR_FAN_LUT description for configuration details. When a controlling temperature exceeds the temperature level programmed in the LUT, the device outputs a PWM duty cycle or adjusts the fan speed, associated with that temperature. See Figure 1 for an example. PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller FAN CONTROL MODE FAN OPERATIONAL DETAILS BIT 6 OF _ FAN_CONFIG_1_2 VALUE IN _ FAN_COMMAND_1 Manual PWM External host controls the fan speed by directly setting the fan PWM duty cycle values. 0 0000h to 7FFFh Manual RPM External host controls the fan speed by setting target fan speed values. The device reads the actual fan speed, and close loop adjusts the output fan PWM to match the target fan speed. 1 0000h to 7FFFh Automatic PWM The device sets the output PWM based on the fan LUT that maps the temperature sensor readings to the required fan PWM duty-cycle values. 0 8000h to FFFFh Automatic RPM The device reads the actual fan speed and close loop adjusts the output fan PWM to match the target fan speed based on the fan LUT that maps the temperature sensor readings to the required fan speed. 1 8000h to FFFFh Note: The RPM modes should only be used with fans that provide a tachometer output. OFFSET ADJUSTMENT ALLOWS TEMPERATURE ZONE NORMALIZATION PAGE 7 I2C REMOTE TEMP SENSOR 0 +15°C PAGE 8 I2C REMOTE TEMP SENSOR 1 +10°C PAGE 9 I2C REMOTE TEMP SENSOR 2 0°C PAGE 10 I2C REMOTE TEMP SENSOR 3 0°C FAN 8 LEVEL LOOKUP TABLE FAN HIGHEST TEMPERATURE CONTROLS THE FAN PAGE 11 REMOTE DIODE TEMP SENSOR +5°C PAGE 6 INTERNAL TEMP SENSOR +5°C Figure 1. Automatic Fan Control 23 MAX34441 Table 7. Fan Control Operation Modes MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller One or all of the six available temperature sensors can be used to control the fan speed. Each temperature sensor has an offset adjustment that allows monitoring specific temperature zones with different thermal characteristics. In Figure 1, I2C temperature sensor 0 is monitoring a zone that is 15NC more sensitive than the zone that the I2C temperature sensor 3 is measuring. To keep the audible noise and fan power consumption as low as possible, the device allows each temperature sensor to have a temperature offset added. This allows temperature zones with different thermal profiles to control the fan at the lowest possible speed to maintain the required temperature. If no temperature sensors are assigned to control the fan, the output fan PWM signal is ramped to 100% duty cycle. In Figure 2, at temperature sample 1, the required fan speed is at the level associated with temperature level 2 and since temperature sample 1 is above temperature level 3, the fan PWM duty cycle needs to be increased to increase the fan speed. The device increases the fan PWM duty cycle at a rate controlled by the RAMP bits in the MFR_FAN_CONFIG command code. If the PWM duty cycle has not reached the target value before the temperature sample detects that a new PWM target value is needed, the device stops moving toward the old target and starts moving to the new target according to the programmed ramp rate. At temperature sample 2, the temperature has increased to greater than temperature level 4 so again the PWM duty cycle must be increased. At temperature sample 3, the temperature has dropped but not below the thermal hysteresis level (which is set by the HYS bits in the MFR_FAN_CONFIG command code), so the fan speed remains at level 4. At temperature sample 4, the temperature has dropped below the hysteresis point so the PWM duty cycle is decreased. Pulse Stretching In some 3-wire fan applications, when the supply power is interrupted to control fan speed, the tachometer signal is not available. Some fan controllers periodically stretch the PWM signal to allow the tachometer to be accurately detected. Pulse stretching can create audible noise. This device does not implement pulse stretching. Hence, the RPM fan modes that require a reliable tachometer signal to be available at all times should not be used in applications that switch power to the fan to control the speed of the fan. For example, low-side switching of a 3-wire fan should not use either of the RPM fan modes. SENSOR TEMPERATURE FAN SPEED T7 S7 T6 THERMAL HYSTERESIS SAMPLED TEMPERATURES T5 S5 SAMPLE 2 SAMPLE 3 T4 T3 S4 SAMPLE 1 SAMPLE 4 S3 T2 S2 T1 S1 T0 S0 ELAPSED TIME TEMPERATURE SAMPLE RATE (ONCE PER SECOND) Figure 2. Fan Speed Example 24 S6 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller 100% SPIN-UP CRITERIA MET AUTOMATIC SPIN-UP ENABLED 90% When spin-up passes, the device forces the fan PWM with a 40% duty cycle. The 40% duty cycle is maintained until the next temperature conversion is completed, which occurs once a second. After the temperature conversion, the device enters either manual mode operation or automatic operation using MFR_FAN_LUT. 80% 70% RAMP PWM TO TARGET PWM OR RPM (CONSTRAINED BY THE RAMP BITS) 60% 50% 40% AUTOMATIC SPIN-UP DISABLED 30% ALWAYS RETURN TO 40% DUTY CYCLE AFTER AUTOMATIC SPIN-UP BEFORE BEGINNING PWM RAMP (EVEN IF BEYOND 1 SECOND) 20% INITIAL TARGET PWM OR RPM DETERMINED AFTER TEMPERATURE CONVERSION 10% 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 TIME (SECONDS) Figure 3. Fan Spin-Up 25 MAX34441 Fan Spin-Up Figure 3 shows the fan spin-up process. When the fan is spinning up, the number of revolutions is checked every 200ms for up to 2s. When the number of cumulated revolutions is greater than or equal to the spin-up relaxation criteria, the fan passes spin-up. If the fan has a locked rotor output, fan spin-up passes when the locked rotor signal is no longer asserted. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller PMBus Commands A summary of the PMBus commands supported by the device are described in the following sections. PAGE (00h) The device can control up to five power supplies, up to six temperature sensors, and a fan using one PMBus (I2C) address. Send the PAGE command with data 0 to 11 to select which power supply or which temperature sensor or fan is affected by all the PMBus commands shown in Table 1. Not all commands are supported within each page. If an unsupported command is received, the CML status bit is set. Some commands are common, meaning that any selected page has the same effect on and the same response from the device. Set the PAGE to 255 when it is desired that the following PMBus commands should apply to all pages at the same time. There are only a few commands (OPERATION, CLEAR_FAULTS) where this function has a real application. Table 8. Page Commands PAGE (DEC) Power Supply Connected to ADC 0 1 Power Supply Connected to ADC 1 2 Power Supply Connected to ADC 2 3 Power Supply Connected to ADC 3 4 Power Supply Connected to ADC 4 5 Fan Connected to PWM 5 6 Internal Temperature Sensor 7 Remote I2C Temperature Sensor with Address 0 8 Remote I2C Temperature Sensor with Address 1 9 Remote I2C Temperature Sensor with Address 2 10 Remote I2C Temperature Sensor with Address 3 11 Remote Thermal-Diode Sensor 12 to 254 255 26 ASSOCIATED CONTROL 0 Reserved Applies to All Pages PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller USER NOTE: All power supplies tagged as GLOBAL supplies (see MFR_FAULT_RESPONSE) should be turned on and off at the same time. Table 9. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 1) COMMAND BYTE POWER SUPPLY ON OR OFF 00h Immediate Off (No Sequencing) MARGIN STATE N/A 40h Soft Off (with Sequencing) N/A 80h On Margin Off 94h On Margin Low (Ignore All Faults) Margin Low (Act On Any Fault) 98h On A4h On Margin High (Ignore All Faults) A8h On Margin High (Act On Any Fault) Note: The device only takes action if the supply is enabled. The VOUT of all enabled channels must exceed POWER_GOOD_ON for margining to begin. Table 10. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 0) COMMAND BYTE POWER SUPPLY ON OR OFF 00h Command Has No Effect MARGIN STATE N/A 40h Command Has No Effect N/A 80h Command Has No Effect Margin Off 94h Command Has No Effect Margin Low (Ignore All Faults) Margin Low (Act On Any Fault) 98h Command Has No Effect A4h Command Has No Effect Margin High (Ignore All Faults) A8h Command Has No Effect Margin High (Act On Any Fault) Note: The device only takes action if the supply is enabled. The VOUT of all enabled channels must exceed POWER_GOOD_ON for margining to begin. 27 MAX34441 OPERATION (01h) The OPERATION command is used to turn the power supply on and off in conjunction with the CONTROL input pin. The OPERATION command is also used to cause the power supply to set the output voltage to the upper or lower margin voltages. The power supply stays in the commanded operating mode until a subsequent OPERATION command or until a change in the state of the CONTROL pin (if enabled) instructs the power supply to change to another state. The valid OPERATION command byte values are shown in Tables 9 and 10. The OPERATION command controls how the device responds when commanded to change the output. When the command byte is 00h, the device immediately turns the power supply off and ignores any programmed turn-off delay. When the command byte is set to 40h, the device powers down according to the programmed turn-off delay. In Tables 9 and 10, “act on any fault” means that if any warning or fault on the selected power supply is detected when the output is margined, the device treats this as a warning or fault and responds as programmed. “Ignore all faults” means that overvoltage, overcurrent, and undervoltage warnings and faults on the selected power supply are ignored and not reported. Any command value not shown in Tables 9 and 10 is an invalid command. If the device receives a data byte that is not listed in Tables 9 and 10, then it treats this as invalid data, declares a data fault (set CML bit and assert ALERT), and responds as described in the Fault Management and Reporting section. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller ON_OFF_CONFIG (02h) The ON_OFF_CONFIG command configures the combination of CONTROL input and PMBus OPERATION commands needed to turn the power supply on and off. This indicates how the power supply is commanded when power is applied. Table 11 describes the ON_OFF_CONFIG message content. The host should not modify ON_OFF_CONFIG while the power supplies are active. Table 11. ON_OFF_CONFIG (02h) Command Byte BIT 7:5 4 PURPOSE Reserved BIT VALUE N/A Turn on supplies when bias is present or use the CONTROL pin and/or OPERATION command 3 OPERATION Command Enable 2 CONTROL Pin Enable 1 CONTROL Pin Polarity 0 CONTROL Pin Turn-Off Action MEANING Always returns 000. 0 Turn on the supplies (with sequencing, if so configured) as soon as bias is supplied to the device regardless of the CONTROL pin. 1 Operate the supplies as instructed by the CONTROL pin and/or the OPERATION command. 0 Ignore the on/off portion of the OPERATION command. 1 OPERATION command enabled and required for action. 0 Ignore the CONTROL pin. 1 CONTROL pin enabled and required for action. 0 Active low (drive low to turn on the power supplies). 1 Active high (drive high to turn on the power supplies). 0 Use the programmed turn-off delay (soft off). 1 Turn off the power supplies immediately. CLEAR_FAULTS (03h) The CLEAR_FAULTS command is used to clear any fault or warning bits in the status registers that have been set. This command clears all bits simultaneously. The CLEAR_FAULTS command does not cause a power supply that has latched off for a fault condition to restart. The status of PSEN under fault conditions is not affected by this command and changes only if commanded through the OPERATION command or CONTROL pin. If a fault is still present after the CLEAR_FAULTS command is executed, the fault status bit is set again and the host is also notified by asserting ALERT (if enabled in MFR_MODE). This command is write-only. There is no data byte for this command. WRITE_PROTECT (10h) The WRITE_PROTECT command is used to provide protection against accidental changes to the device operating memory. All supported commands can have their parameters read, regardless of the WRITE_PROTECT settings. The WRITE_PROTECT message content is described in Table 12. Table 12. WRITE_PROTECT Command Byte COMMAND BYTE MEANING 80h Disable all writes except the WRITE_PROTECT command. 40h Disable all writes except the WRITE_PROTECT, OPERATION, and PAGE commands. 20h Disable all writes except the WRITE_PROTECT, OPERATION, PAGE, and ON_OFF_CONFIG commands. 00h Enable writes for all commands (default). Note: No fault or error is generated if the host attempts to write to a protected area. 28 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller USER NOTE: VDD must be above 2.9V for the device to perform the STORE_DEFAULT_ALL command. RESTORE_DEFAULT_ALL (12h) The RESTORE_DEFAULT_ALL command transfers the default configuration information from the internal flash memory array to the user memory registers in the device. The RESTORE_DEFAULT_ALL command should only be executed when the device is not operating the power supplies or fans. Upon a device reset, this command is automatically executed by the device without PMBus action required. This command is write-only. There is no data byte for this command. CAPABILITY (19h) The CAPABILITY command is used to determine some key capabilities of the device. The CAPABILITY command is read-only. The message content is described in Table 13. Table 13. CAPABILITY Command Byte BIT 7 6:5 4 3:0 DESCRIPTION MEANING Packet-Error Checking 0 = PEC not supported. PMBus Speed 00 = Maximum supported bus speed is 100kHz. ALERT 1 = Device supports an ALERT output (if ALERT is enabled in MFR_MODE). 0 = Device does not support ALERT output (ALERT is disabled in MFR_MODE). Reserved Always returns 0000. VOUT_MODE (20h) The VOUT_MODE command is used to report the data format of the device. The device uses the DIRECT format for all the voltage-related commands. The value returned is 40h, indicating DIRECT data format. This command is read-only. If a host attempts to write this command, the CML status bit is asserted. See Table 3 for the m, b, and R values for the various commands. VOUT_MARGIN_HIGH (25h) The VOUT_MARGIN_HIGH command loads the device with the voltage to which the power-supply output is to be changed when the OPERATION command is set to margin high. If the power supply is already operating at margin high, changing VOUT_MARGIN_HIGH has no effect on the output voltage. The device only adjusts the power supply to the new VOUT_MARGIN_HIGH voltage after receiving a new margin high OPERATION command. The 2 data bytes are in DIRECT format. If the device cannot successfully close-loop margin the power supply, the device keeps attempting to margin the supply and does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the MARGIN_FAULT bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE). 29 MAX34441 STORE_DEFAULT_ALL (11h) The STORE_DEFAULT_ALL command instructs the device to transfer the device configuration information to the internal flash memory array. Not all information is stored. Only configuration data is stored, not any status, or operational data. If an error occurs during the transfer, ALERT asserts if enabled and the CML bit in STATUS_BYTE and STATUS_WORD is set to 1. No bits are set in STATUS_CML. It is NOT recommended to use the STORE_DEFAULT_ALL command while the device is operating power supplies or fans. The device is unresponsive to PMBus commands and does not monitor power supplies while transferring the configuration. This command is write-only. There is no data byte for this command. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller VOUT_MARGIN_LOW (26h) The VOUT_MARGIN_LOW command loads the device with the voltage to which the power-supply output is to be changed when the OPERATION command is set to margin low. If the power supply is already operating at margin low, changing VOUT_MARGIN_LOW has no effect on the output voltage. The device only adjusts the power supply to the new VOUT_MARGIN_LOW voltage after receiving a new margin low OPERATION command. The 2 data bytes are in DIRECT format. If the device cannot successfully close-loop margin the power supply, the device keeps attempting to margin the supply and does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the MARGIN_FAULT bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE). VOUT_SCALE_MONITOR (2Ah) VOUT_SCALE_MONITOR is used in applications where the measured power-supply voltage is not equal to the voltage at the ADC input. For example, if the ADC input expects a 1.0V input for a 12V output, VOUT_SCALE_MONITOR = 1.0V/12V = 0.0833. In applications where the power-supply output voltage is greater than the device input range, the output voltage of the power supply is sensed through a resistive voltage-divider. The resistive voltage-divider reduces or scales the output voltage. The PMBus commands specify the actual power-supply output voltages and not the input voltage to the ADC. To allow the device to map between the power-supply voltage (such as 12V) and the voltage at the ADC input, the VOUT_SCALE_MONITOR command is used. The 2 data bytes are in DIRECT format. This value is dimensionless. For example, if the required scaling factor is 0.0833, then VOUT_SCALE_MONITOR should be set to 0AABh (2731/32,767 = 0.0833). Table 14. VOUT_SCALE_MONITOR NOMINAL VOLTAGE LEVEL MONITORED (V) NOMINAL ADC INPUT VOLTAGE LEVEL (V) (SEE NOTE) RESISTIVE VOLTAGEDIVIDER RATIO VOUT_SCALE_MONITOR VALUE (HEX) 1.2 1.0 0.833 6AAAh 1.5 1.0 0.667 5555h 1.8 1.0 0.555 470Ah 2.5 1.0 0.4 3333h 3.3 1.0 0.303 26C8h 5 1.0 0.2 1999h 12 1.0 0.0833 0AABh Note: On the device, the full-scale ADC voltage is 1.225V. A scaling factor where a 1.0V ADC input represents a nominal 100% voltage level is recommended. IOUT_CAL_GAIN (38h) The IOUT_CAL_GAIN command is used to set the ratio of the voltage at the ADC input to the sensed current. The units of the IOUT_CAL_GAIN factor are 0.1mI. The 2 data bytes are in DIRECT format. For example, if a 10mI sense resistor is used with a 50V/V current-sense amplifier, the IOUT_CAL_GAIN should be set to 500mI or 1388h. USER NOTE: On the device, the full-scale ADC voltage is 1.225V. The value of the sense resistor and currentsense amplifier gain must be scaled appropriately. 30 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 15. FAN_CONFIG_1_2 Command Byte BIT NAME 7 FAN ENABLE 6 RPM/PWM 5:4 PULSE 3:0 0 MEANING 0 = Fan disabled (PWM5 forced low). 1 = Fan enabled. 0 = PWM duty cycle is the fan-controlling parameter. 1 = RPM is the fan-controlling parameter. 00 01 10 11 = = = = 1 2 3 4 Tach Tach Tach Tach pulse per fan revolution. pulses per fan revolution. pulses per fan revolution. pulses per fan revolution. These bits always return a 0. FAN_COMMAND_1 (3Bh) The FAN_COMMAND_1 command is used to override the device’s automatic fan-control function and force the fan to either a fixed PWM duty-cycle value or a target fan speed (in RPM). The units of the FAN_COMMAND_1 are either percent duty cycle (if bit 6 of FAN_CONFIG_1_2 is zero) or RPM (if bit 6 of FAN_CONFIG_1_2 is one). Any value less than 0% duty cycle or 0 RPM causes the device to ignore this command and use the automatic fan-control function. Any value greater than or equal to 0% duty cycle or 0 RPM causes the device to ignore the automatic fan-control function and force the fan to the PWM value or RPM value provided by the FAN_COMMAND_1 command. The 2 data bytes are in DIRECT format. Table 16. PWM Fan Mode (FAN_CONFIG_1_2 Bit 6 = 0) FAN_COMMAND_1 VALUE DEVICE RESPONSE 8000h to FFFFh Ignore FAN_COMMAND_1 and use automatic fan-control function 0000h to 2710Fh 0 to 100% fan PWM duty cycle 2711h to 7FFFh 100% fan PWM duty cycle Table 17. RPM Fan Mode (FAN_CONFIG_1_2 Bit 6 = 1) FAN_COMMAND_1 VALUE DEVICE RESPONSE 8000h to FFFFh Ignore FAN_COMMAND_1 and use automatic fan-control function 0000h to 7FFFh 0 to 32,767 RPM 31 MAX34441 FAN_CONFIG_1_2 (3Ah) The FAN_CONFIG_1_2 command is used in conjunction with MFR_FAN_CONFIG to configure the fan. See the MFR_FAN_CONFIG (F1h) section for more details on this command. The FAN_CONFIG_1_2 command is described in Table 15. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller VOUT_OV_FAULT_LIMIT (40h) The VOUT_OV_FAULT_LIMIT command sets the value of the output voltage that causes an output overvoltage fault. The 2 data bytes are in DIRECT format. In response to the VOUT_OV_FAULT_LIMIT being exceeded, the device does the following: 1) Sets the VOUT_OV bit in STATUS_BYTE. 2) Sets the VOUT_OV and VOUT bits in STATUS_WORD. 3) Sets the VOUT_OV_FAULT bit in STATUS_VOUT. 4) Responds as specified in the MFR_FAULT_RESPONSE. 5) Notifies the host through ALERT assertion (if enabled in MFR_MODE). VOUT_OV_WARN_LIMIT (42h) The VOUT_OV_WARN_LIMIT command sets the value of the output voltage that causes an output-voltage high warning. This value is typically less than the output overvoltage threshold in VOUT_OV_FAULT_LIMIT. The 2 data bytes are in DIRECT format. In response to the VOUT_OV_WARN_LIMIT being exceeded, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and VOUT bits in STATUS_WORD. 3) Sets the VOUT_OV_WARN bit in STATUS_VOUT. 4) Notifies the host using ALERT assertion (if enabled in MFR_MODE). VOUT_UV_WARN_LIMIT (43h) The VOUT_UV_WARN_LIMIT command sets the value of the output voltage that causes an output-voltage low warning. This value is typically greater than the output undervoltage fault threshold in VOUT_UV_FAULT_LIMIT. This warning is masked until the output voltage reaches the programmed VOUT_UV_FAULT for the first time, and also during turn-off when the power supply is disabled. The 2 data bytes are in DIRECT format. In response to violation of the VOUT_UV_ WARN_LIMIT, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and VOUT bits in STATUS_WORD. 3) Sets the VOUT_UV_WARN bit in STATUS_VOUT. 4) Notifies the host using ALERT assertion (if enabled in MFR_MODE). VOUT_UV_FAULT_LIMIT (44h) The VOUT_UV_FAULT_LIMIT command sets the value of the output voltage that causes an output undervoltage fault. This fault is masked until the output voltage reaches the programmed VOUT_UV_FAULT for the first time, and also during turn-off when the power supply is disabled. The VOUT_UV_FAULT_LIMIT threshold is also used to determine if TON_MAX_FAULT_LIMIT is exceeded. The 2 data bytes are in DIRECT format. In response to violation of the VOUT_ UV_FAULT_LIMIT, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and VOUT bits in STATUS_WORD. 3) Sets the VOUT_UV_FAULT bit in STATUS_VOUT. 4) Responds as specified in MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE). 32 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE, IOUT, and MFR bits in STATUS_WORD. 3) Sets the OC_WARN bit in STATUS_MFR_SPECIFIC. 4) Notifies the host using ALERT assertion (if enabled in MFR_MODE). IOUT_OC_FAULT_LIMIT (4Ah) The IOUT_OC_FAULT_LIMIT command sets the value of the current that causes an overcurrent fault. The factory default value for IOUT_OC_FAULT_LIMIT is 0000h. This value disables the device from measuring current. Any nonzero positive value written to IOUT_OC_FAULT_LIMIT causes the device to enable current measurement. The 2 data bytes are in DIRECT format. In response to violation of the IOUT_OC_FAULT_LIMIT, the device does the following: 1) Sets the IOUT_OC bit in STATUS_BYTE. 2) Sets the IOUT, IOUT_OC, and MFR bits in STATUS_WORD. 3) Sets the OC_FAULT bit in STATUS_MFR_SPECIFIC. 4) Responds as specified in the MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE). Table 18. IOUT_OC_FAULT_LIMIT IOUT_OC_FAULT_LIMIT VALUE 8000h to FFFFh DEVICE RESPONSE (ON THE ASSOCIATED PAGE) Negative values are invalid. 0000h Current measurement disabled. 0001h to 7FFFh Current measurement enabled. OT_FAULT_LIMIT (4Fh) The OT_FAULT_LIMIT command sets the temperature, in degrees Celsius, of the selected temperature sensor at which an overtemperature fault is detected. The 2 data bytes are in DIRECT format. In response to the OT_FAULT_LIMIT being exceeded, the device does the following: 1) Sets the TEMPERATURE bit in STATUS_BYTE. 2) Sets the TEMPERATURE and MFR bits in STATUS_WORD. 3) Sets the OT_FAULT bit in STATUS_MFR_SPECIFIC. 4) Responds as specified in MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE). 33 MAX34441 IOUT_OC_WARN_LIMIT (46h) The IOUT_OC_WARN_LIMIT command sets the value of the current that causes an overcurrent warning. This value is typically less than the overcurrent fault threshold in IOUT_OC_FAULT_LIMIT. The 2 data bytes are in DIRECT format. In response to violation of the IOUT_OC_WARN_LIMIT, the device does the following: MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller OT_WARN_LIMIT (51h) The OT_WARN_LIMIT command sets the temperature, in degrees Celsius, of the selected temperature sensor at which an overtemperature warning is detected. The 2 data bytes are in DIRECT format. In response to the OT_WARN_LIMIT being exceeded, the device does the following: 1) Sets the TEMPERATURE bit in STATUS_BYTE. 2) Sets the TEMPERATURE and MFR bits in STATUS_WORD. 3) Sets the OT_WARN bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE). POWER_GOOD_ON (5Eh) The POWER_GOOD_ON command sets the value of the output voltage that causes the PG output (if enabled in MFR_MODE) to assert. All enabled power supplies must be above their associated POWER_GOOD_ON thresholds before the PG output is asserted. All the enabled power supplies must also be above POWER_GOOD_ON for powersupply margining to begin. The POWER_GOOD_ON level is normally set higher than the POWER_GOOD_OFF level and VOUT_UV_FAULT_LIMIT. The 2 data bytes are in DIRECT format. POWER_GOOD_OFF (5Fh) The POWER_GOOD_OFF command sets the value of the output voltage that causes the PG output (if enabled in MFR_MODE) to deassert after it has been asserted. Any enabled power supply that falls below the associated POWER_GOOD_OFF threshold causes the PG output to be deasserted. The POWER_GOOD_OFF level is normally set lower than the POWER_GOOD_ON level. The 2 data bytes are in DIRECT format. When the VOUT level of a power supply falls from greater than POWER_GOOD_ON to less than POWER_GOOD_OFF, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE, POWER_GOOD#, AND MFR bits in STATUS_WORD. 3) Sets the POWER_GOOD# bit in STATUS_MFR_SPECIFIC. OPERATION COMMAND CODE OR CONTROL PIN TON_DELAY TOFF_DELAY PSEN PIN (ACTIVE HIGH OR LOW/ OPEN DRAIN OR PUSH-PULL) TON_MAX_FAULT_LIMIT POWER_GOOD_ON VOUT_UV_FAULT_LIMIT ADC INPUT POWER_GOOD# BIT IN STATUS_MFR_SPECIFIC Figure 4. Power-Supply Sequencing 34 POWER_GOOD_OFF PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller TON_MAX_FAULT_LIMIT (62h) The TON_MAX_FAULT_LIMIT sets an upper time limit, in milliseconds, from when the TON_DELAY and the PSEN output are asserted until the output voltage crosses the VOUT_UV_FAULT_LIMIT threshold. The 2 data bytes are in DIRECT format. If the value is 0, the power supply is not sequenced by the device and the associated PSEN output remains deasserted; voltage and current monitoring is disabled. In response to the TON_MAX_FAULT_LIMIT being exceeded, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and VOUT bits in STATUS_WORD. 3) Sets the TON_MAX_FAULT bit in STATUS_VOUT. 4) Responds as specified in the MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE). Table 19. TON_MAX_FAULT_LIMIT TON_MAX_FAULT_LIMIT VALUE 8000h to FFFFh 0000h DEVICE RESPONSE (FOR THE ASSOCIATED PAGE) Negative values are invalid. Channel off (PSEN remains deasserted with no monitoring). 0001h to 7FFFh Channel on and sequencing enabled. TOFF_DELAY (64h) The TOFF_DELAY sets the time, in milliseconds, from when a STOP condition is received (a soft-off OPERATION command or through the CONTROL pin when enabled) until the PSEN output is deasserted. When commanded to turn off immediately (either through the OPERATION command or the CONTROL pin), the TOFF_DELAY value is ignored. The 2 data bytes are in DIRECT format. STATUS_BYTE (78h) The STATUS_BYTE command returns 1 byte of information with a summary of the most critical faults. A value of 1 indicates that a fault or warning event has occurred and a 0 indicates otherwise. Bits for unsupported features are reported as 0. The STATUS_BYTE cannot be restored by the RESTORE_DEFAULT_ALL command. The STATUS_BYTE message content is described in Table 20. This command is read-only. Table 20. STATUS_BYTE BIT BIT NAME 7:6 0 5 VOUT_OV An overvoltage fault has occurred. 4 IOUT_OC An overcurrent fault has occurred. 3 0 2 TEMPERATURE 1 CML 0 MEANING These bits always return a 0. This bit always returns a 0. A temperature fault or warning has occurred. A communication, memory, or logic fault has occurred. NONE OF THE ABOVE A fault or warning not listed in bits [7:1] has occurred. 35 MAX34441 TON_DELAY (60h) TON_DELAY sets the time, in milliseconds, from when a START condition is received (a valid OPERATION command or through the CONTROL pin when enabled) until the PSEN output is asserted. The undervoltage fault and warning are masked off during TON_DELAY. The 2 data bytes are in DIRECT format. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller STATUS_WORD (79h) The STATUS_WORD command returns 2 bytes of information with a summary of the reason for a fault. The low byte of the STATUS_WORD is the same data as the STATUS_BYTE. Table 21 describes the STATUS_WORD message content. Table 21. STATUS_WORD BIT BIT NAME 15 VOUT An output voltage fault or warning or TON_MAX_FAULT has occurred. 14 IOUT An overcurrent fault or warning has occurred. 13 0 12 MFR 11 POWER_GOOD# 10 FANS 9:6 0 5 VOUT_OV 4 IOUT_OC 3 0 2 TEMPERATURE 1 CML 0 MEANING This bit always returns a 0. A bit in STATUS_MFR_SPECIFIC has been set. A power-supply voltage has fallen from POWER_GOOD_ON to less than POWER_GOOD_OFF. A fan fault has occurred. These bits always return a 0. An overvoltage fault has occurred. An overcurrent fault has occurred. This bit always returns a 0. A temperature fault or warning has occurred. A communication, memory, or logic fault has occurred. NONE OF THE ABOVE A fault or warning not listed in bits [7:1] has occurred. STATUS_VOUT (7Ah) The STATUS_VOUT command returns 1 byte of information with contents as described in Table 22. Table 22. STATUS_VOUT BIT BIT NAME 7 VOUT_OV_FAULT VOUT overvoltage fault. MEANING 6 VOUT_OV_WARN VOUT overvoltage warning. 5 VOUT_UV_WARN VOUT undervoltage warning. 4 VOUT_UV_FAULT 3 0 2 TON_MAX_FAULT 1:0 0 VOUT undervoltage fault. This bit always returns a 0. TON maximum fault. These bits always return a 0. STATUS_CML (7Eh) The STATUS_CML command returns 1 byte of information with contents as described in Table 23. Table 23. STATUS_CML 36 BIT BIT NAME 7 COMM_FAULT 6 DATA_FAULT 5:1 0 0 FAULT_LOG_FULL MEANING An invalid or unsupported command has been received. An invalid or unsupported data has been received. These bits always return a 0. MFR_NV_FAULT_LOG is full and needs to be cleared. PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 24. STATUS_MFR_SPECIFIC BIT BIT NAME 7 OFF MEANING This bit is set if the power supply is off (due to either a fault or sequencing delay; this bit is not set if the power supply is disabled). 6 OT_WARN Overtemperature warning. 5 OT_FAULT Overtemperature fault. 4 WATCHDOG A watchdog reset has occurred. 3 MARGIN_FAULT This bit is set if the device cannot properly close-loop margin the power supply. 2 POWER_GOOD# Power-supply voltage has fallen from POWER_GOOD_ON to less than POWER_GOOD_OFF. 1 OC_FAULT IOUT overcurrent fault. 0 OC_WARN IOUT overcurrent warning. Note: The settings of the OFF and POWER_GOOD# bits do not assert the ALERT signal. STATUS_FANS_1_2 (81h) The STATUS_FANS_1_2 command returns 1 byte of information with the status of the fan. The STATUS_FANS_1_2 command is described in Table 25. Table 25. STATUS_FANS_1_2 BIT BIT NAME 7 FAN_1_FAULT 6 0 5 FAN_1_WARN 4:0 0 MEANING Fan 1 fault. This bit always returns a 0. Fan 1 warning. These bits always return a 0. READ_VOUT (8Bh) The READ_VOUT command returns the actual measured (not commanded) output voltage. READ_VOUT is measured and updated every 5ms. The 2 data bytes are in DIRECT format. READ_IOUT (8Ch) The READ_IOUT command returns the latest measured current value. READ_IOUT is measured and updated every 200ms. The 2 data bytes are in DIRECT format. READ_TEMPERATURE_1 (8Dh) The READ_TEMPERATURE_1 command returns the temperature returned from the temperature sensor. The value of READ_TEMPERATURE_1 does not have offset from MFR_TEMP_SENSOR_CONFIG added. READ_TEMPERATURE_1 returns 7FFFh if the sensor is faulty and 0000h if the sensor is disabled. READ_TEMPERATURE_1 is measured and updated once a second. The 2 data bytes are in DIRECT format. 37 MAX34441 STATUS_MFR_SPECIFIC (80h) The STATUS_MFR_SPECIFIC command returns 1 byte of information with a summary of the reason for a fault. The STATUS_MFR_SPECIFIC message content is described in Table 24. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller READ_FAN_SPEED_1 (90h) The READ_FAN_SPEED_1 command returns the fan speed in RPM. READ_FAN_SPEED_1 is updated once a second, even if the fan is disabled. The PULSE bits in FAN_CONFIG_1_2 must be properly configured to receive the correct fan speed. Fan speeds below 60 RPM (360 RPM for dual mode fans) are reported as 0 RPM. The 2 data bytes are in DIRECT format. PMBUS_REVISION (98h) The PMBUS_REVISION command returns the revision of the PMBus specification to which the device is compliant. The command has 1 data byte. Bits [7:4] indicate the revision of PMBus specification Part I to which the device is compliant. Bits [3:0] indicate the revision of PMBus specification Part II to which the device is compliant. This command is read-only. The PMBUS_REVISION value returned is always 11h, which indicates that it is compliant with Part I Rev 1.1 and Part II Rev 1.1. MFR_ID (99h) The MFR_ID command returns the text (ISO/IEC 8859-1) character of the manufacturer’s (Maxim) identification. The default MFR_ID value is 4Dh (M). This command is read-only. MFR_MODEL (9Ah) The MFR_MODEL command returns the text (ISO/IEC 8859-1) character of the device model number. The default MFR_MODEL value is 52h (R). This command is read-only. MFR_REVISION (9Bh) The MFR_REVISION command returns two text (ISO/IEC 8859-1) characters that contain the device revision numbers for hardware (upper byte) and firmware (lower byte). The default MFR_REVISION value is 3031h (01). This command is read-only. MFR_LOCATION (9Ch) The MFR_LOCATION command loads the device with text (ISO/IEC 8859-1) characters that identify the facility that manufactures the power supply. The maximum number of characters is 8. This data is written to internal flash using the STORE_DEFAULT_ALL command. The factory default text string value is 3130313031303130h. MFR_DATE (9Dh) The MFR_DATE command loads the device with text (ISO/IEC 8859-1) characters that identify the date of manufacture of the power supply. The maximum number of characters is 8. This data is written to internal flash using the STORE_DEFAULT_ALL command. The factory default text string value is 3130313031303130h. MFR_SERIAL (9Eh) The MFR_SERIAL command loads the device with text (ISO/IEC 8859-1) characters that uniquely identify the device. The maximum number of characters is 8. This data is written to internal flash using the STORE_DEFAULT_ALL command. The factory default text string value is 3130313031303130h. 38 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 26. MFR_MODE BIT BIT NAME MEANING FORCE_NV_FAULT_LOG Setting this bit to 1 forces the device to log data into the nonvolatile fault log. Once set, the device clears this bit when the action is completed. The host must set again for subsequent action. If an error occurs during this action, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML. 14 CLEAR_NV_FAULT_LOG Setting this bit to 1 forces the device to clear the nonvolatile fault log by writing FFh to all byte locations. Once set, the device clears this bit when the action is completed. The host must set again for subsequent action. If an error occurs during this action, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML. 13 ALERT 15 12 0 11 SOFT_RESET 10:9 PGTIME[1:0] 8 PG_SELECT 7 PSEN_PP_OD 6 PSEN_HI_LO 5:0 0 0 = ALERT disabled (device does not respond to ARA). 1 = ALERT enabled (device responds to ARA and ARA must be used). This bit always returns a 0. This bit must be set, then cleared and set again within 8ms for a soft reset to occur. PGTIME1 PGTIME0 TIME FROM POWER GOOD DETERMINED UNTIL PG OUTPUT IS ASSERTED (ms) 0 0 Immediately 0 1 100 1 0 500 1 1 1000 0 = PG/TACHSEL output is power-good indication. 1 = PG/TACHSEL output is TACHSEL (for dual tachometer fans). For dual tachometer fans, this output is toggled every 500ms. Applies to all PSEN outputs. 0 = PSEN push-pull output. 1 = PSEN open-drain output. Applies to all PSEN outputs. 0 = PSEN active low. 1 = PSEN active high. These bits always return a 0. Note: If a dual tachometer fan is used, it is recommended that the slower tachometer signal be presented to the TACH pin when TACHSEL = 0. 39 MAX34441 MFR_MODE (D1h) The MFR_MODE command is used to configure the device to support manufacturer specific commands. The MFR_ MODE command is described in Table 26. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_VOUT_PEAK (D4h) The MFR_VOUT_PEAK command returns the maximum actual measured output voltage. To reset this value to 0, write to this command with a data value of 0. Any values written to this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECT format. MFR_IOUT_PEAK (D5h) The MFR_IOUT_PEAK command returns the maximum measured current. To reset this value to 0, write to this command with a data value of 0. Any values written to this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECT format. MFR_TEMPERATURE_PEAK (D6h) The MFR_TEMPERATURE_PEAK command returns the maximum measured temperature. To reset this value to its lowest value, write to this command with a data value of 8000h. Any other values written by this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECT format. MFR_VOUT_MIN (D7h) The MFR_VOUT_MIN command returns the minimum actual measured output voltage. To reset this value, write to this command with a data value of 7FFFh. Any values written to this command are used as a comparison for future minimum updates. The 2 data bytes are in DIRECT format. MFR_FAULT_RESPONSE (D9h) The MFR_FAULT_RESPONSE command specifies the response to each fault condition supported by the device. In response to a fault, the device always report the fault in the appropriate status register and asserts the ALERT output (if enabled in MFR_MODE). A CML fault cannot cause any device action other than setting the status bit and asserting the ALERT output. The MFR_FAULT_RESPONSE command is described in Table 27. Table 27. MFR_FAULT_RESPONSE BIT BIT NAME 15 NV_LOG 0 = Do not log the fault into MFR_NV_FAULT_LOG. 1 = Log the fault into MFR_NV_FAULT_LOG. 14 GLOBAL 0 = Affect only the selected page power supply. 1 = Affect all supplies with GLOBAL = 1. 13:12 0 MEANING These bits always return a 0. 11:10 MFR_FAN_FAULT_LIMIT_RESPONSE[1:0] See Table 28. 9:8 IOUT_OC_FAULT_LIMIT_RESPONSE[1:0] See Table 28. 7:6 5:4 OT_FAULT_LIMIT_RESPONSE[1:0] See Table 28 (see Note 1). TON_MAX_FAULT_LIMIT_RESPONSE[1:0] See Table 28. 3:2 VOUT_UV_FAULT_LIMIT_RESPONSE[1:0] See Table 28. 1:0 VOUT_OV_FAULT_LIMIT_RESPONSE[1:0] See Table 28. Note 1: All enabled temperature sensor faults are logically ORed together. Note 2: Temperature and fan faults affect all enabled power supplies. Supplies that are designated as global all respond in the same manner. This response is the worst-case response of the global channels for the given fault. Supplies that are not global respond to a temperature or fan fault based upon the programmed response for the particular supply. Note 3: The fault response for a power-supply fault is determined by the programmed fault response for the faulting channel. If this channel is part of a global group, this fault response is performed for all the global channels. 40 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller RESPONSE [1:0] 11 FAULT RESPONSE • • • Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. Continue power-supply operation. • Shut down the power supply by deasserting the PSEN output. Wait for the time configured in MFR_FAULT_RETRY and restart the supply. If GLOBAL = 1, all enabled power supplies with GLOBAL = 1 are shut down in sequence as configured with TOFF_DELAY, or they are all shut down immediately as configured by bit 0 in ON_OFF_CONFIG. Wait for the time configured in MFR_FAULT_RETRY and restart supplies in sequence as configured with TON_DELAY. If GLOBAL = 1, assert the FAULT output until faults on all GLOBAL supplies clear and MFR_FAULT_RETRY expires. Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. 10 • • • • 01 00 • • • Latch-off the power supply by deasserting the PSEN output. If GLOBAL = 1, all enabled power supplies with GLOBAL = 1 are either shut down in sequence as configured with TOFF_DELAY, or they are all shut down immediately as configured by bit 0 in ON_OFF_CONFIG. Assert the FAULT output if GLOBAL = 1 until power supplies are restarted by the user. Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. • • Set the corresponding fault bit in the appropriate status register. Continue power-supply operation. Note: ALERT is asserted if enabled when a new status bit is set. A status bit is latched the first time a particular fault or warning occurs. MFR_FAULT_RETRY (DAh) The MFR_FAULT_RETRY command sets the delay time between a power supply being shut down by a fault response and the power supply restarting. This command sets the retry time delay in multiples of 1ms. This command value is used for all fault responses that require delay retry. If global supplies are being sequenced off, the retry delay time does not begin until the last global channel is turned off. The 2 data bytes are in DIRECT format. When MFR_FAULT_RETRY = 0000h, the device restarts the power supply at the next available time period. MFR_NV_FAULT_LOG (DCh) Each time the MFR_NV_FAULT_LOG command is executed, the device returns a block of 255 bytes containing one of the 15 nonvolatile fault logs. The MFR_NV_FAULT_LOG command must be executed 15 times to dump the complete nonvolatile fault log. If the returned fault log is all FFs, this indicates that this fault log has not been written by the device. As the device is operating, it is reading the latest operating conditions for voltage, current, temperature, and fan speed, and it is updating the status registers. All this information is stored in on-board RAM. When a fault is detected (if so enabled in MFR_FAULT_RESPONSE), the device automatically logs this information to one of the 15 nonvolatile fault logs. After 15 faults have been written, bit 0 of STATUS_CML is set and the host must clear the fault log by setting the CLEAR_NV_FAULT_LOG bit in MFR_MODE before any additional faults are logged. All the latest status information is logged as well as eight readings of voltage from the last 800ms in 100ms increments and four readings of current from the last 800ms of operation. If a power supply is not enabled to measure either current or voltage or if a temperature sensor is disabled, the associated fault log position returns 0000h. There is a FAULT_LOG_COUNT (16-bit counter) at the beginning of each fault log that indicates which fault log is the latest. This counter rolls over should more than 65,535 faults be logged. This counter is not cleared when the CLEAR_NV_FAULT_LOG bit in MFR_MODE is toggled. The 255 bytes returned by the MFR_NV_FAULT_LOG command are described in Table 29. 41 MAX34441 Table 28. MFR_FAULT_RESPONSE Codes MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller EACH FAULT IS WRITTEN INTO THE NEXT FAULT LOG FLASH EACH COMMAND READ ACCESSES THE NEXT FAULT LOG FAULT LOG INDEX 0 (255 BYTES) RAM FAULT LOG INDEX 1 (255 BYTES) STATUS VOLTAGE CURRENT TEMPERATURE FAN SPEED FAULT OCCURENCE MFR_NV_FAULT_LOG FAULT LOG INDEX 2 (255 BYTES) FAULT LOG INDEX 14 (255 BYTES) Figure 5. MFR_NV_FAULT_LOG If an error occurs while the device is attempting to write or clear the NV_FAULT_LOG, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML. ALERT is asserted (if enabled in MFR_MODE). See Figure 5. USER NOTE: VDD must be above 2.9V for the device to clear or log data into MFR_NV_FAULT_LOG. Table 29. MFR_NV_FAULT_LOG BYTE 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 PARAMETER 00h/FAULT_LOG_INDEX FAULT_LOG_COUNT MFR_TIME_COUNT (LSW) MFR_TIME_COUNT (MSW) STATUS_BYTE/STATUS_CML STATUS_WORD STATUS_VOUT Pages 0/1 STATUS_VOUT Pages 2/3 STATUS_VOUT Page 4/00h STATUS_MFR_SPECIFIC Pages 0/1 STATUS_MFR_SPECIFIC Pages 2/3 STATUS_MFR_SPECIFIC Pages 4/00h STATUS_MFR_SPECIFIC Pages 6/7 STATUS_MFR_SPECIFIC Pages 8/9 STATUS_MFR_SPECIFIC Pages 10/11 RESERVED (0000h) STATUS_FANS_1_2/00h MFR_VOUT_PEAK Page 0 MFR_VOUT_PEAK Page 1 MFR_VOUT_PEAK Page 2 MFR_VOUT_PEAK Page 3 BYTE 128 130 132 134 136 138 140 142 144 146 148 150 152 154 156 158 160 162 164 166 168 PARAMETER READ_VOUT Index = 3, Page 2 READ_VOUT Index = 3, Page 3 READ_VOUT Index = 3, Page 4 RESERVED (0000h) READ_VOUT Index = 4, Page 0 READ_VOUT Index = 4, Page 1 READ_VOUT Index = 4, Page 2 READ_VOUT Index = 4, Page 3 READ_VOUT Index = 4, Page 4 RESERVED (0000h) READ_VOUT Index = 5, Page 0 READ_VOUT Index = 5, Page 1 READ_VOUT Index = 5, Page 2 READ_VOUT Index = 5, Page 3 READ_VOUT Index = 5, Page 4 RESERVED (0000h) READ_VOUT Index = 6, Page 0 READ_VOUT Index = 6, Page 1 READ_VOUT Index = 6, Page 2 READ_VOUT Index = 6, Page 3 READ_VOUT Index = 6, Page 4 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller BYTE 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 104 106 108 110 112 114 116 118 120 122 124 126 PARAMETER MFR_VOUT_PEAK Page 4 RESERVED (0000h) MFR_IOUT_PEAK Page 0 MFR_IOUT_PEAK Page 1 MFR_IOUT_PEAK Page 2 MFR_IOUT_PEAK Page 3 MFR_IOUT_PEAK Page 4 RESERVED (0000h) MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_VOUT_MIN Page 0 MFR_VOUT_MIN Page 1 MFR_VOUT_MIN Page 2 MFR_VOUT_MIN Page 3 MFR_VOUT_MIN Page 4 RESERVED (0000h) RESERVED (0000h) RESERVED (0000h) VOLTAGE_INDEX/00h READ_VOUT Index = 0, Page 0 READ_VOUT Index = 0, Page 1 READ_VOUT Index = 0, Page 2 READ_VOUT Index = 0, Page 3 READ_VOUT Index = 0, Page 4 RESERVED (0000h) READ_VOUT Index = 1, Page 0 READ_VOUT Index = 1, Page 1 READ_VOUT Index = 1, Page 2 READ_VOUT Index = 1, Page 3 READ_VOUT Index = 1, Page 4 RESERVED (0000h) READ_VOUT Index = 2, Page 0 READ_VOUT Index = 2, Page 1 READ_VOUT Index = 2, Page 2 READ_VOUT Index = 2, Page 3 READ_VOUT Index = 2, Page 4 RESERVED (0000h) READ_VOUT Index = 3, Page 0 READ_VOUT Index = 3, Page 1 6 7 8 9 10 11 BYTE 170 172 174 176 178 180 182 184 186 188 190 192 194 196 198 200 202 204 206 208 210 212 214 216 218 220 222 224 226 228 230 232 234 236 238 240 242 244 246 248 250 252 254 MAX34441 Table 29. MFR_NV_FAULT_LOG (continued) PARAMETER RESERVED (0000h) READ_VOUT Index = 7, Page 0 READ_VOUT Index = 7, Page 1 READ_VOUT Index = 7, Page 2 READ_VOUT Index = 7, Page 3 READ_VOUT Index = 7, Page 4 RESERVED (0000h) RESERVED (0000h) CURRENT_INDEX/00h READ_IOUT Index = 0, Page 0 READ_IOUT Index = 0, Page 1 READ_IOUT Index = 0, Page 2 READ_IOUT Index = 0, Page 3 READ_IOUT Index = 0, Page 4 RESERVED (0000h) READ_IOUT Index = 1, Page 0 READ_IOUT Index = 1, Page 1 READ_IOUT Index = 1, Page 2 READ_IOUT Index = 1, Page 3 READ_IOUT Index = 1, Page 4 RESERVED (0000h) READ_IOUT Index = 2, Page 0 READ_IOUT Index = 2, Page 1 READ_IOUT Index = 2, Page 2 READ_IOUT Index = 2, Page 3 READ_IOUT Index = 2, Page 4 RESERVED (0000h) READ_IOUT Index = 3, Page 0 READ_IOUT Index = 3, Page 1 READ_IOUT Index = 3, Page 2 READ_IOUT Index = 3, Page 3 READ_IOUT Index = 3, Page 4 RESERVED (0000h) RESERVED (0000h) READ_TEMPERATURE_1 Page 6 READ_TEMPERATURE_1 Page 7 READ_TEMPERATURE_1 Page 8 READ_TEMPERATURE_1 Page 9 READ_TEMPERATURE_1 Page 10 READ_TEMPERATURE_1 Page 11 READ_FAN_SPEED_1 MFR_READ_FAN_PWM LOG_VALID (see note) Note: LOG_VALID is set to DDh if the fault log contains valid data. 43 MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_TIME_COUNT (DDh) The MFR_TIME_COUNT command returns the number of seconds the device has been operating since the last time power was applied to the device, RST was toggled, or a soft reset occurred. The counter is a 32-bit value and cannot be reset by the user. MFR_MARGIN_CONFIG (E0h) The MFR_MARGIN_CONFIG command configures the digital PWM outputs to margin the power supplies. The MFR_MARGIN_CONFIG command is described in Table 30. Power-supply margining is implemented using the PWM outputs. The PWM frequency is 62.5kHz. The device close-loop controls the duty cycle to margin the power supply. The device provides 6 bits of duty-cycle resolution. The device margins the power supplies when OPERATION is set to one of the margin states. Margining of the supplies does not begin until all enabled power supplies have exceeded their programmed POWER_GOOD_ON levels. When this happens, the PWM output is enabled and the seed value from MFR_MARGIN_CONFIG is loaded as the initial PWM duty cycle. The device then averages eight samples of VOUT for a total time of 40ms. If the measured VOUT and the target (set by either VOUT_MARGIN_HIGH or VOUT_MARGIN_LOW) differ by more than 1%, the PWM duty cycle is adjusted by one step. The direction of the duty cycle adjustment is determined by the SLOPE bit in MFR_MARGIN_CONFIG. All changes to the PWM are made after averaging eight samples of VOUT over a 40ms period. The device is unable to successfully margin a power supply to the programmed target when the PWM duty cycle reaches 0% or 100% and the target voltage has not been achieved. If this occurs, the device continues attempting to margin the power supply and does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the MARGIN_FAULT bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE). Also, the averaged VOUT after the PWM has initially been enabled with the seed value is compared to the target value. If the programmed seed value causes VOUT to exceed the target, a MARGIN_FAULT is declared. For example, if the target is VOUT_MARGIN_LOW and VOUT is less than VOUT_MARGIN_LOW after seeding, MARGIN_FAULT is set. In response to this fault, the device continues margining the power supply and does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the MARGIN_FAULT bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE). Table 30. MFR_MARGIN_CONFIG 44 BIT BIT NAME 15 SLOPE 14:6 0 5:0 SEED MEANING PWM duty cycle to resulting voltage relationship. 0 = Negative slope (increasing duty cycle results in a lower voltage). 1 = Positive slope (increasing duty cycle results in a higher voltage). These bits always return a 0. This 6-bit value is used as the initial PWM duty cycle (i.e., seed value) when the device begins to margin a power supply either up or down. PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Table 31. MFR_TEMP_SENSOR_CONFIG BIT 15 BIT NAME ENABLE MEANING 0 = Temperature sensor disabled. 1 = Temperature sensor enabled. The OFFSET setting is used to allow the temperature reading to be normalized among multiple temperature sensors. Values from 00h to 1Eh select the offset value. The valid range is 0NC to +30NC in 1NC steps. If OFFSET is 1Fh, the device automatically uses the value written to the OT_WARN_LIMIT command code for the LUT instead of the digitized measured temperature. OFFSET VALUE 14:10 OFFSET 9:1 0 0 FAN CONFIGURATION 00h Offset = 0NC 01h Offset = +1NC 02h Offset = +2NC 1Dh Offset = +29NC 1Eh Offset = +30NC 1Fh Test Mode These bits always return a 0. 0 = Temperature sensor is not used to control fan speed. 1 = Temperature sensor is used to control fan speed. 45 MAX34441 MFR_TEMP_SENSOR_CONFIG (F0h) The MFR_TEMP_SENSOR_CONFIG command is used to configure the temperature sensors. Table 31 describes the MFR_TEMP_SENSOR_CONFIG command. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_FAN_CONFIG (F1h) The MFR_FAN_CONFIG command is used with FAN_CONFIG_1_2 to configure the fan. See the FAN_CONFIG_1_2 description for more details on this command. Table 32 described the MFR_FAN_CONFIG command. Table 32. MFR_FAN_CONFIG BIT BIT NAME MEANING The FREQ bits set the PWM frequency. Note: The device does not support pulse stretching. 15:13 12 FREQ[2:0] 0 FREQ2 FREQ1 FREQ0 PWM FREQUENCY 0 0 0 30Hz 0 0 1 50Hz 0 1 0 100Hz 0 1 1 150Hz 1 0 0 Reserved 1 0 1 Reserved 1 1 0 Reserved 1 1 1 25kHz This bit always returns a 0. The HYS bits determine the amount of hysteresis the device uses to determine how far the temperature must fall below the temperature level threshold programmed in the LUT before switching to the lower PWM/RPM value. The hysteresis should be set lower than the minimum difference between two adjacent temperature steps. These bits are ignored if automatic fan control is disabled. 11:10 9 8 46 HYS[1:0] TSFO TACHO HSY1 HSY0 THERMAL HYSTERESIS (NC) 0 0 2 0 1 4 1 0 6 1 1 8 0 = Ramp to 100% PWM duty cycle if temp sensor faults (automatic fan mode) or if no FAN_COMMAND_1 update occurs (manual fan mode) in any 10s period. 1 = Temp sensor fault or update rate to FAN_COMMAND_1 is ignored. Operate at the last updated PWM/RPM value. Note 1: A temp sensor fault is a faulty temperature sensor reading, not an overtemperature fault. Note 2: In automatic fan mode, if the TSFO bit is set to 1, the device ignores a sensor fault and uses the remaining assigned temperature sensors (if any) to control the fan PWM duty cycle; or, if the fan has no available temperature sensors to use, it maintains the last updated PWM/RPM fan value before the fault occurred. 0 = Ramp fan to 100% PWM duty cycle if fan fault is detected. 1 = Do not ramp fan to 100% PWM duty cycle if fan fault is detected. Note: If the fan fault is removed after ramping the PWM to 100% duty cycle, normal fan operation is resumed. PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller BIT BIT NAME MEANING The RAMP bits select how fast the device ramps the PWM from one duty cycle to another (either up or down). In PWM mode, the following table always applies. In RPM mode, the fan speed is read either every 200ms or 1000ms and when the reported fan speed is within 20% of the target speed, the maximum allowed PWM duty cycle change is set to 1%. In RPM mode, the PWM duty cycle is not changed as long as the fan is within Q5% of the target speed. RAMP2 7:5 4 3 RAMP[2:0] 0 ROTOR_HI_LO RAMP1 RAMP0 PWM DUTY_ CYCLE UPDATE RATE (ms) TIME TO RAMP MAX PWM DUTY_ FROM 40% TO CYCLE CHANGE 100% PWM DUTY ALLOWED (%) CYCLE (seconds) 0 0 0 1000 1 60 0 0 1 1000 2 30 0 1 0 1000 3 20 0 1 1 200 1 12 1 0 0 200 2 6 1 0 1 200 3 4 1 1 0 200 4 3 1 1 1 200 5 2.4 This bit always returns a 0. Determines if a locked rotor indication is active low or active high. This bit is ignored if ROTOR = 0. 0 = ROTOR is active low (TACH input is low if the rotor stops). 1 = ROTOR is active high (TACH input is high if the rotor stops). The ROTOR bit selects if the fan does not have a tachometer but rather a stalled (or locked) rotor output. 2 1:0 ROTOR SPIN[1:0] ROTOR FAN OUTPUT 0 Tachometer 1 Stalled/locked rotor detect MAX34441 CONFIGURATION TACH input expects fan RPM TACH input expects locked rotor signal. The polarity is selected with the ROTOR_HI_LO bit (also set MFR_FAN_FAULT_LIMIT = 0001h). The SPIN bits determine how the device spins up (or starts) the fan from a dead stop. To overcome the initial mechanical fan inertia, the device can be programmed to drive the fan at 100% duty cycle until a programmable number of fan revolutions (cumulative count) is detected or a locked rotor signal is negated. The device allows a 2s startup period during which the fan speed monitors are disabled. If after 2s the fan does not respond, the PWM output remains at 100% duty cycle (if TACHO = 0) or goes to 0% duty cycle (if TACHO = 1). SPIN1 SPIN0 0 0 Automatic spin-up disabled 0 1 Two revolutions or locked rotor negated 1 0 Four revolutions or locked rotor negated 1 1 Eight revolutions or locked rotor negated SPIN-UP RELAXATION CRITERIA Note: It is recommended that the fan be disabled prior to changing MFR_FAN_CONFIG. 47 MAX34441 Table 32. MFR_FAN_CONFIG (continued) MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_FAN_LUT (F2h) The MFR_FAN_LUT command is used to configure the LUT that controls the fan. The fan has an LUT that maps eight programmable temperature levels to eight programmable fan PWM duty-cycle levels (bit 6 in FAN_CONFIG_1_2 is zero) or eight programmable target fan speeds (bit 6 in FAN_CONFIG_1_2 is one). The LUT allows a wide variety of profiles to be used. USER NOTE: The programmable configuration of MFR_FAN_LUT must be monotonic. Table 33. MFR_FAN_LUT BYTE NUMBER WORD NAME 0-1 TEMP STEP 0 Temperature for step 0. MEANING 2-3 SPEED STEP 0 Fan PWM duty cycle or fan speed for step 0. 4-5 TEMP STEP 1 Temperature for step 1. 6-7 SPEED STEP 1 Fan PWM duty cycle or fan speed for step 1. 8-9 TEMP STEP 2 Temperature for step 2. 10-11 SPEED STEP 2 Fan PWM duty cycle or fan speed for step 2. 12-13 TEMP STEP 3 Temperature for step 3. 14-15 SPEED STEP 3 Fan PWM duty cycle or fan speed for step 3. 16-17 TEMP STEP 4 Temperature for step 4. 18-19 SPEED STEP 4 Fan PWM duty cycle or fan speed for step 4. 20-21 TEMP STEP 5 Temperature for step 5. 22-23 SPEED STEP 5 Fan PWM duty cycle or fan speed for step 5. 24-25 TEMP STEP 6 Temperature for step 6. 26-27 SPEED STEP 6 Fan PWM duty cycle or fan speed for step 6. 28-29 TEMP STEP 7 Temperature for step 7. 30-31 SPEED STEP 7 Fan PWM duty cycle or fan speed for step 7. TEMPERATURE STEP: Temperature Level Setting The TEMPERATURE STEP sets the temperature in degrees Celsius and represents a threshold level at which the device updates the fan PWM duty cycle setting. The 2 data bytes are in DIRECT format. The valid temperature range depends on the temperature sensor. Table 34. Valid Temperature Range TEMPERATURE SENSOR VALID RANGE Page 6: Internal Temp Sensor -40NC to +85NC Pages 7 to 10: I2C Remote Temp Sensor -55NC to +125NC Page 11: Remote Thermal Diode Temp Sensor -40NC to +120NC 48 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller If bit 6 in FAN_CONFIG_1_2 is set to 1, the FAN SPEED STEP sets the fan target speed (in RPM) at each temperature step breakpoint. The valid fan speed range is 0 to 32,767 (inclusive). THERMAL HYSTERESIS MAXIMUM DESIRED FAN DUTY CYCLE OR SPEED S7 S6 S5 S4 FAN PWM DUTY CYCLE OR FAN SPEED (IN RPM) S3 S2 S1 S0 PWM = 0% DUTY CYCLE T0 T1 T2 T3 T4 T5 T6 T7 NORMALIZED TEMPERATURE (FROM ONE OR MORE TEMP SENSORS) Figure 6. Fan Lookup Table (LUT) Format 49 MAX34441 FAN SPEED STEP: Fan PWM Duty Cycle or Fan Speed Setting If bit 6 in FAN_CONFIG_1_2 is set to zero, the FAN SPEED STEP sets the fan PWM duty cycle at each temperature step breakpoint. The valid duty cycle range is 0 to 100 (inclusive). Any values greater than 100 (decimal) result in 100% PWM duty cycle being generated, and any values less than 0 (decimal) result in 0% PWM duty cycle. MAX34441 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MFR_READ_FAN_PWM (F3h) The MFR_READ_FAN_PWM command returns the latest real-time value for the fan PWM in % duty cycle. MFR_READ_FAN_PWM is updated whenever the PWM duty cycle is updated. This is determined by the RATE bits in MFR_FAN_CONFIG. The 2 data bytes are in DIRECT format. MFR_FAN_FAULT_LIMIT (F5h) The MFR_FAN_FAULT_LIMIT command sets the value of the fan speed (in RPM) or percentage of target fan speed that causes a fan fault. Fans operating below these limits for over 10s continuous trip the fault. When the fan is operating in RPM mode, the 10s checking period starts after the device has completed a PWM ramp of the fan speed. The slowest tachometer signal the device can measure for a fan is 60 RPM. In dual tachometer applications, the slowest RPM is 360. Tachometer signals slower than these minimums are reported as 0 RPM. Fault and warning limits should be set to RPM values greater than these minimum RPM limits. The 2 data bytes are in DIRECT format. Set to 0000h to disable the limit checking. Set to 0001h to only alarm when the tachometer input is locked for greater than 10s (this mode should be used when the fan only has a locked rotor output). In response to violation of the MFR_FAN_FAULT_LIMIT or if a stalled/locked rotor is detected, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and FANS bits in STATUS_WORD. 3) Sets the FAN_1_FAULT bit in STATUS_FANS_1_2. 4) Responds as specified in the MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE). USER NOTE: For proper fan operation, MFR_FAN_FAULT_LIMIT must be configured. MFR_FAN_WARN_LIMIT (F6h) The MFR_FAN_WARN_LIMIT command sets the value of the fan speed (in RPM) or percentage of target fan speed that causes a fan speed warning. Fans operating below these limits for over 10s continuous trip the warning. When the fan is operating in RPM mode, the 10s checking period starts after the device has completed a PWM ramp of the fan speed. Normally, the MFR_FAN_WARN_LIMIT is set higher than the MFR_FAN_FAULT_LIMIT. The 2 data bytes are in DIRECT format. Set to 0000h to disable the limit checking. Set to 0001h to generate a warning when using a locked rotor fan. In response to violation of the MFR_FAN_WARN_LIMIT, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and FANS bits in STATUS_WORD. 3) Sets the FAN_1_WARN bit in STATUS_FANS_1_2. 4) Notifies the host using ALERT assertion (if enabled in MFR_MODE). Table 35. Monitored Fan Fault and Warning Parameters FAN CONTROL MODE 50 LIMIT PARAMETER COMPARISON INTERVAL Manual PWM Fan speed (in RPM) Checked once a second Manual RPM Percentage of programmed target fan speed Checked once a second Automatic PWM Fan speed (in RPM) Checked once a second Automatic RPM Percentage of LUT target fan speed Checked once a second PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller Power-Supply Decoupling To achieve the best results when using the device, decouple the VDD power supply with a 0.1FF capacitor. Use a high-quality, ceramic, surface-mount capacitor if possible. Surface-mount components minimize lead inductance, which improves performance, and ceramic capacitors tend to have adequate high-frequency response for decoupling applications. Open-Drain Pins MSDA, MSCL, SCL, SDA, FAULT, and ALERT are opendrain pins and require external pullup resistors connected to VDD to realize high logic levels. PSEN0 to PSEN4 can be user-configured as either CMOS push-pull or open-drain outputs. When configured as open-drain, external pullup resistors connected to VDD are required to realize high logic levels (see the MFR_MODE settings). Decouple the REG25 and REG18 regulator outputs using 1FF and 10nF capacitors (one each per output). 51 MAX34441 Applications Information PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller MAX34441 Typical Operating Circuit INPUT VOLTAGE IN OUT POWER SUPPLY MAX9938 CURRENT-SENSE AMPLIFIER TRIM EN UP TO 4 CHANNELS MSCL +3.3V VSS SDA SCL OPTIONAL SUPPORT FOR CURRENT MONITORING FROM MUXSEL PSEN1 PWM1 RS-1 RS+1 VDD HOST INTERFACE SPDT MUX 5 CHANNELS PSEN0 PWM0 RS-0 RS+0 MSDA DS75LV I2C TEMP SENSOR LOAD MAX34441 RST ALERT FAULT A0/MUXSEL A1/PG/TACHSEL PSEN2 PWM2 RS-2 RS+2 PSEN3 PWM3 RS-3 RS+3 PSEN4 PWM4 RS-4 RS+4 REG25 RS+5 REG18 RS-5 PWM5 TACH5 REMOTE TEMPERATURE DIODE OPTIONAL SUPPORT FOR DUAL FANS SPDT MUX FROM TACHSEL Package Information For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 52 PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 40 TQFN-EP T4066+2 21-0141 90-0053 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller REVISION NUMBER REVISION DATE 0 8/10 Initial release 1/12 Changed the lead temperature from +260°C to +300°C in the Absolute Maximum Ratings section; changed the VIL(MIN) and VI2C_IL(MIN) specs from -0.3V to 0V in the Recommended Operating Conditions table; changed the INL(MAX) spec from ±4 LSB to ±8LSB and removed the DNL parameter in the DC Electrical Characteristics table; changed the 9Bh code default value from 3030h to 3031h in Table 1 and the MFR_REVISION (9Bh) section; updated the third bullet for “Undervoltage” in Table 5; changed reference of “POWER_GOOD_ON voltage at startup” to “VOUT_UV_FAULT for the first time” in the VOUT_UV_WARN_LIMIT (43h) and VOUT_UV_FAULT_LIMIT (44h) sections; updated the POWER_GOOD_OFF (5Fh) section; added “and FANS bits” to number 2 condition in the MFR_FAN_ WARN_LIMIT (F6h) section 1 DESCRIPTION PAGES CHANGED — 6, 7, 15, 21, 32, 34, 38, 50 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2012 Maxim Integrated Products 53 Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX34441 Revision History