MAXIM MAX34440

19-5527; Rev 0; 9/10
PMBus 6通道电源管理器
MAX34440 是一款复杂系统监测器，可管理多达 6 路电源。
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。
应用
特性
♦♦6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
网络交换机 / 路由器
♦♦支持多达8个温度传感器
基站
♦♦2个远端二极管温度传感器
服务器
♦♦5个本地温度传感器
智能电网系统
♦♦1个内部温度传感器
工业控制
♦♦对所有温度传感器进行故障检测
♦♦PMBus™兼容命令接口
♦♦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
MAX34440ETL+
PART
-40NC to +85NC
40 TQFN-EP*
MAX34440ETL+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。
MAX34440
概述
MAX34440
PMBus 6通道电源管理器
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
发送 DIRECT格式数据 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
故障管理和报告. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
系统看门狗定时器 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
温度传感器操作 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
2
PMBus 6通道电源管理器
PMBus 命令. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
PAGE(00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
OPERATION(01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
ON_OFF_CONFIG(02h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
CLEAR_FAULTS(03h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
WRITE_PROTECT(10h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
STORE_DEFAULT_ALL(11h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
RESTORE_DEFAULT_ALL(12h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
CAPABILITY(19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
VOUT_MODE(20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
VOUT_MARGIN_HIGH(25h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
VOUT_MARGIN_LOW(26h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
VOUT_SCALE_MONITOR(2Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
IOUT_CAL_GAIN(38h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
VOUT_OV_FAULT_LIMIT(40h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
VOUT_OV_WARN_LIMIT(42h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
VOUT_UV_WARN_LIMIT(43h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
VOUT_UV_FAULT_LIMIT(44h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
IOUT_OC_WARN_LIMIT(46h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
IOUT_OC_FAULT_LIMIT(4Ah)................................................. 29
OT_FAULT_LIMIT(4Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
OT_WARN_LIMIT(51h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
POWER_GOOD_ON(5Eh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
POWER_GOOD_OFF(5Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
TON_DELAY(60h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
TON_MAX_FAULT_LIMIT(62h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
TOFF_DELAY(64h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
STATUS_BYTE(78h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
STATUS_WORD(79h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
STATUS_VOUT(7Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
STATUS_CML(7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
STATUS_MFR_SPECIFIC(80h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
READ_VOUT(8Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
READ_IOUT(8Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
READ_TEMPERATURE_1(8Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
PMBUS_REVISION(98h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
MFR_ID(99h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
3
MAX34440
目录 ( 续 )
MAX34440
PMBus 6通道电源管理器
目录 ( 续 )
MFR_MODEL(9Ah). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
MFR_REVISION(9Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
MFR_LOCATION(9Ch). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
MFR_DATE(9Dh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
MFR_SERIAL(9Eh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
MFR_MODE(D1h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
MFR_VOUT_PEAK(D4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
MFR_IOUT_PEAK(D5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
MFR_TEMPERATURE_PEAK(D6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
MFR_VOUT_MIN(D7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
MFR_FAULT_RESPONSE(D9h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
MFR_FAULT_RETRY(DAh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
MFR_NV_FAULT_LOG(DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
MFR_TIME_COUNT(DDh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
MFR_MARGIN_CONFIG(E0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
MFR_TEMP_SENSOR_CONFIG(F0h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
应用信息 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
电源去耦 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
开漏引脚 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
典型工作电路 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
封装信息 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
修订历史 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4
PMBus 6通道电源管理器
图1. 电源排序 .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
图2.MFR_NV_FAULT_LOG .
表目录
表1.PMBus 命令代码 .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
表5. 器件参数监测状态 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
表 6.DS75LV地址引脚配置 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
表7. 页命令. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
表 8.OPERATION 命令字节(ON_OFF_CONFIG 的第 3 位=1时) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
表9.OPERATION 命令字节(ON_OFF_CONFIG 的第 3 位=0 时) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
表10.ON_OFF_CONFIG(02h) 命令字节. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
表11.WRITE_PROTECT命令字节 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
表12.CAPABILITY命令字节 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
表13.VOUT_SCALE_MONITOR................................................. 27
表14.IOUT_OC_FAULT_LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
表15.TON_MAX_FAULT_LIMIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
表16.STATUS_BYTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
表17.STATUS_WORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
表18.STATUS_VOUT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
表19.STATUS_CML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
表 20.STATUS_MFR_SPECIFIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
表 21.MFR_MODE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
表 22.MFR_FAULT_RESPONSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
表 23.MFR_FAULT_RESPONSE 编码. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
表 24.MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
表 24.MFR_NV_FAULT_LOG(续) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
表 25.MFR_MARGIN_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
表 26.MFR_TEMP_SENSOR_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
表1.PMBus 命令代码(续) .
5
MAX34440
图目录
MAX34440
PMBus 6通道电源管理器
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 6通道电源管理器
(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
-3
LSB
LSB
LSB
Q2
TA = -40NC to +85NC
V
FV
12
ADC Integral Nonlinearity
ADC Offset
TYP
-1
ADC Measurement Resolution
ADC Differential Nonlinearity
MIN
+3
NC
Store Default All Time
37
ms
Nonvolatile Log Write Time
12
ms
Nonvolatile Log Delete Time
200
Flash Endurance
Data Retention
NFLASH
ms
TA = +50NC
20,000
Write
Cycles
TA = +50NC
100
Years
Voltage Sample Rate
5
ms
Current Sample Rate
200
ms
Temperature Sample Rate
1000
ms
12
ms
Device Startup Time
Measurement from POR until monitoring
begins
PWM Frequency
Power supply
62.5
kHz
PWM Resolution
Power supply
6
Bits
7
MAX34440
DC Electrical characteristics (continued)
MAX34440
PMBus 6通道电源管理器
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 6通道电源管理器
(TA = +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. TEMPERATURE
2.5
2.5
2.4
IDD (mA)
2.4
IDD (mA)
MAX34440 toc02
2.6
MAX34440 toc01
2.6
2.3
VDD = 3.3V
2.3
TA = +25°C
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 NONVOLATILE LOG WRITE
(TA = +25°C, VDD = 3.3V)
MAX34440 toc03
MAX34440 toc04
C1 = PSEN0
0V
C3 = PWM0
0V
1mA/div
1V/div
C2 = VDD
0V
0A
1ms/div
2ms/div
FILTERED MARGINING VOLTAGE
vs. TIME DURING MARGIN UP
MAX34440 toc05
200mV/div
0V
100ms/div
9
MAX34440
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
17 PSEN5
FAULT 34
CONTROL 35
16 PWM5
MAX34440
15 MSCL
VSS 36
14 MSDA
A1/PG 37
ALERT 38
+
RS-5 39
13 RST
EP
12 RS-2
11 RS+2
5
6
RS+4
RS-3
RS+3
RS+0
7
8
9
10
RS-1
4
VDD
3
RS-0
2
RS+1
1
VSS
RS+5 40
RS-4
MAX34440
PMBus 6通道电源管理器
TQFN
(6mm × 6mm × 0.75mm)
引脚说明
引脚
功能
RS-4
ADC4电压测量的地参考端。
2, 21, 36
VSS
数字电源回路节点(地)。
3
RS+4
4
RS-3
1
10
名称
5
RS+3
6
RS+0
7
RS-0
8
RS+1
9
VDD
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。
10
RS-1
11
RS+2
12
RS-2
13
14
RST
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
17
PSEN5
PWM 裕量调节输出#5。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#5。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。
低电平有效复位输入。
PMBus 6通道电源管理器
引脚
名称
功能
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。
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。
20
PWM3
22
REG18
23
PSEN3
24
PWM2
25
PSEN2
26
PWM1
27
PSEN1
28
PWM0
29
REG25
30
PSEN0
31
SDA
32
SCL
33
A0/MUXSEL
34
FAULT
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
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。
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
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。
38
ALERT
低电平有效、开漏报警输出。
11
MAX34440
引脚说明(续)
引脚说明(续)
引脚
名称
39
RS-5
40
RS+5
—
EP
功能
ADC5电压测量的地参考端。
电源 ADC电压检测输入，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。
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
SMBus
MASTER
INTERFACE
PSEN1
PSEN2
PSEN3
PSEN4
PSEN5
SMBus
SLAVE
INTERFACE
ADC
SYSTEM
CONTROL
SIGNALS
MAX34440
12
16-BIT
MAXQ
RISC CORE
POWERSUPPLY
OUTPUT
ENABLES
MUX
MAX34440
PMBus 6通道电源管理器
RAM
FLASH
TEMP
SENSOR
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 6通道电源管理器
+3.3V
ALERT
HOST
INTERFACE
CLOCK
DATA
CONTROL
RST
SDA
SCL
RST
ALERT
MAX34440
#0
FAULT
CONTROL
A1/PG
A0/MUXSEL
+3.3V
SDA
SCL
RST
ALERT
FAULT
MAX34440
#1
CONTROL
A1/PG
A0/MUXSEL
ADDITIONAL DEVICES
13
MAX34440
多器件连接框图
MAX34440
PMBus 6通道电源管理器
温度监测功能可支持多达 8 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 MAX6695 双
通道远端 / 本地温度传感器。通过专用的I2 C/SMBus 接口与
DS75LV 和 MAX6695温度传感器通信。
详细说明
MAX34440 是一款高度 集 成的系统 监 测器， 基 于16 位、
MAXQ微控制器，带有工厂可编程功能，可监测多达 6 路
电源。器件具有电源闭环控制和本地 / 远端温度检测功能。
器件提供 ALERT 和 FAULT 输出信号，主器件通过 PMBus 兼
容端口进行通信。提供地址输入连接，允许系统I/O总线上
挂接 4片 MAX34440 器件。
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。
表1. PMBus命令代码
CODE
COMMAND NAME
TYPE
PAGE
0–5
PAGE
6–13
PAGE
255
NO. OF BYTES
FLASH STORED
(NOTE 2)
DEFAULT
VALUE
(NOTE 2)
R/W
1
N
00h
(NOTE 1)
00h
PAGE
R/W Byte
R/W
01h
OPERATION
R/W Byte
R/W
—
W
1
N
00h
02h
ON_OFF_CONFIG
R/W Byte
R/W
R/W
R/W
1
Y
1Ah
03h
CLEAR_FAULTS
Send Byte
W
W
W
0
N
—
10h
WRITE_PROTECT
R/W Byte
R/W
R/W
R/W
1
N
00h
11h
STORE_DEFAULT_ALL
Send Byte
W
W
W
0
N
—
12h
RESTORE_DEFAULT_ALL
Send Byte
W
W
W
0
N
—
19h
CAPABILITY
Read Byte
R
R
R
1
N
00h/10h
20h
VOUT_MODE
Read Byte
R
R
R
1
FIXED
40h
25h
VOUT_MARGIN_HIGH
R/W Word
R/W
—
—
2
Y
0000h
26h
VOUT_MARGIN_LOW
R/W Word
R/W
—
—
2
Y
0000h
2Ah
VOUT_SCALE_MONITOR
R/W Word
R/W
—
—
2
Y
7FFFh
38h
IOUT_CAL_GAIN
R/W Word
R/W
—
—
2
Y
0000h
40h
VOUT_OV_FAULT_LIMIT
R/W Word
R/W
—
—
2
Y
7FFFh
42h
VOUT_OV_WARN_LIMIT
R/W Word
R/W
—
—
2
Y
7FFFh
43h
VOUT_UV_WARN_LIMIT
R/W Word
R/W
—
—
2
Y
0000h
44h
VOUT_UV_FAULT_LIMIT
R/W Word
R/W
—
—
2
Y
0000h
46h
IOUT_OC_WARN_LIMIT
R/W Word
R/W
—
—
2
Y
7FFFh
4Ah
IOUT_OC_FAULT_LIMIT
R/W Word
R/W
—
—
2
Y
0000h
4Fh
OT_FAULT_LIMIT
R/W Word
—
R/W
—
2
Y
7FFFh
51h
OT_WARN_LIMIT
R/W Word
—
R/W
—
2
Y
7FFFh
5Eh
POWER_GOOD_ON
R/W Word
R/W
—
—
2
Y
0000h
5Fh
POWER_GOOD_OFF
R/W Word
R/W
—
—
2
Y
0000h
MAXQ 是 MaximIntegratedProducts,Inc. 的注册商标。
14
R/W
PMBus 6通道电源管理器
CODE
COMMAND NAME
TYPE
PAGE
0–5
PAGE
6–13
PAGE
255
(NOTE 1)
NO. OF BYTES
FLASH STORED
(NOTE 2)
DEFAULT
VALUE
(NOTE 2)
60h
TON_DELAY
R/W Word
R/W
—
—
2
Y
0000h
62h
TON_MAX_FAULT_LIMIT
R/W Word
R/W
—
—
2
Y
0000h
64h
TOFF_DELAY
R/W Word
R/W
—
—
2
Y
0000h
78h
STATUS_BYTE
Read Byte
R
R
R
1
N
00h
79h
STATUS_WORD
Read Word
R
R
R
2
N
0000h
7Ah
STATUS_VOUT
Read Byte
R
—
—
1
N
00h
7Eh
STATUS_CML
Read Byte
R
R
R
1
N
00h
80h
STATUS_MFR_SPECIFIC
Read Byte
R
R
—
1
N
00h
8Bh
READ_VOUT
Read Word
R
—
—
2
N
0000h
8Ch
READ_IOUT
Read Word
R
—
—
2
N
0000h
8Dh
READ_TEMPERATURE_1
Read Word
—
R
—
2
N
0000h
98h
PMBUS_REVISION
Read Byte
R
R
R
1
FIXED
11h
99h
MFR_ID
Read Byte
R
R
R
1
FIXED
4Dh
9Ah
MFR_MODEL
Read Byte
R
R
R
1
FIXED
51h
9Bh
MFR_REVISION
Read Word
R
R
R
2
FIXED
3030h
9Ch
MFR_LOCATION
Block R/W
R/W
R/W
R/W
8
Y
(Note 3)
9Dh
MFR_DATE
Block R/W
R/W
R/W
R/W
8
Y
(Note 3)
9Eh
MFR_SERIAL
Block R/W
R/W
R/W
R/W
8
Y
(Note 3)
D1h
MFR_MODE
R/W Word
R/W
R/W
R/W
2
Y
0000h
D4h
MFR_VOUT_PEAK
R/W Word
R/W
—
—
2
N
0000h
D5h
MFR_IOUT_PEAK
R/W Word
R/W
—
—
2
N
0000h
D6h
MFR_TEMPERATURE_PEAK
R/W Word
—
R/W
—
2
N
8000h
D7h
MFR_VOUT_MIN
R/W Word
R/W
—
—
2
N
7FFFh
D9h
MFR_FAULT_RESPONSE
R/W Word
R/W
—
—
2
Y
0000h
DAh
MFR_FAULT_RETRY
R/W Word
R/W
R/W
R/W
2
Y
0000h
DCh
MFR_NV_FAULT_LOG
Block Read
R
R
R
255
Y
(Note 4)
DDh
MFR_TIME_COUNT
Block Read
R
R
R
4
N
(Note 5)
E0h
MFR_MARGIN_CONFIG
R/W Word
R/W
—
—
2
Y
0000h
F0h
MFR_TEMP_SENSOR_CONFIG
R/W Word
—
R/W
—
2
Y
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。
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。
15
MAX34440
表1. PMBus命令代码(续)
MAX34440
PMBus 6通道电源管理器
表 2. PMBus/SMBus串口地址
7-BIT SLAVE
ADDRESS
A1
A0
100kI to VSS
100kI to VSS
100kI to VDD
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。
1101 010 (D4h)
SMBus/PMBus 操作
1101 011 (D6h)
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。数
据传输为最高有效位(MSB) 在前。
100kI to VSS
1101 100 (D8h)
100kI to VDD
1101 101 (DAh)
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
WRITE WORD FORMAT
1
7
1
1
8
1
8
1
8
1
1
S
SLAVE
ADDRESS
W
A
COMMAND
CODE
A
DATA BYTE
LOW
A
DATA BYTE
HIGH
A
P
WRITE BYTE FORMAT
1
7
1
1
8
1
8
1
1
S
SLAVE
ADDRESS
W
A
COMMAND
CODE
A
DATA BYTE
A
P
1
8
1
1
A
COMMAND
CODE
A
P
SEND BYTE FORMAT
16
1
7
S
SLAVE
ADDRESS
1
W
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 6通道电源管理器
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
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
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)
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。
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
17
MAX34440
群发命令
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
PMBus 6通道电源管理器
MAX34440
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 6通道电源管理器
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 (tTO)，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，
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
MAX34440，该器件与一个电源器件配合工作。由于命令
可能要求打开或关闭 PMBus 器件，MAX34440 将始终保持
工作，保持与 PMBus 主器件的通信，MAX34440 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。
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 MAX34440) 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。
19
MAX34440
主器件从只写命令请求读操作
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：
MAX34440
PMBus 6通道电源管理器
表3. PMBus命令代码系数
PARAMETER
Voltage
Voltage Scaling
Current
Current Scaling
Temperature
Timing
COMMANDS
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
VOUT_SCALE_MONITOR
IOUT_OC_WARN_LIMIT
IOUT_OC_FAULT_LIMIT
READ_IOUT
MFR_IOUT_PEAK
IOUT_CAL_GAIN
OT_FAULT_LIMIT
OT_WARN_LIMIT
READ_TEMPERATURE_1
MFR_TEMPERATURE_PEAK
TON_DELAY
TON_MAX_FAULT_LIMIT
TOFF_DELAY
MFR_FAULT_RETRY
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)x10R
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。
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。
表4. DIRECT格式数据的系数
COMMAND CODE
20
COMMAND NAME
m
b
R
25h
VOUT_MARGIN_HIGH
1
0
0
8Bh
READ_VOUT
1
0
0
UNITS
RESOLUTION
MAX
m
b
R
mV
1
32,767
1
0
0
—
1/32,767
1
32,767
0
0
mA
1
32,767
1
0
0
mI
0.1
3276.7
1
0
1
NC
0.01
327.67
1
0
2
ms
1
32,767
1
0
0
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：
Y=(1x3465+0)x10 0=3465(十进制)=
0D89h(十六进制)
相反，如果主器件在 READ_VOUT命令后收到 0D89h，则
相当于：
X=(1/1)x(0D89hx10 -(-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。
PMBus 6通道电源管理器
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。
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：
•通过 CONTROL引脚、OPERATION 命令或 CONTROL引脚
和 OPERATION 命令共同作用来关闭输出，然后再打开。
•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。
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。
表5. 器件参数监测状态
PARAMETER
Overvoltage
Undervoltage
Overcurrent
Power-Up Time
Overtemperature
REQUIRED CONDITIONS FOR ACTIVE MONITORING
Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h)
•
•
•
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
•
•
Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h)
Current Monitoring Enabled (IOUT_OC_FAULT_LIMIT ≠ 0000h)
Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h)
Temp Sensor Enabled (ENABLE in MFR_TEMP_SENSOR_CONFIG = 1)
ACTION DURING A FAULT
Continue Monitoring
Stop Monitoring While the Power
Supply is Off
Continue Monitoring
Monitor Only During Power-On
Continue Monitoring
21
MAX34440
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。
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。
MAX34440
PMBus 6通道电源管理器
温度传感器操作
器件可监测多达 8 个不同的温度传感器 (7个外部传感器和
1 个自身内部的温 度传感 器)。外部温 度传感 器 并联 连 接
至 主机I2 C 端口(MSDA 和 MSCL引脚)。器件支持多达 4片
DS75LV 和1个 MAX6695。每秒钟对每个使能的温度传感
器进行一次测量。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，二极管发生开路或短路时被认为发生故
障。对于内部温度传感器，读数大于 +130 °C 或小于 -60 °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。读取被禁用的温度传感器将返回固
定值 0000h。
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。
器件可控制一个 MAX6695(由一个本地温度传感器和 2 个
远端二极管温度传感器构成 )。通过 MFR_TEMP_SENSOR_
CONFIG 禁用、然后重新使能传感器，可以对每一路温度传
感器重新初始化。MAX6695温度传感器的有效范围为 -40°C
至+125°C，页分配如表 6 所示。MAX6695 的 ALERT、OT1
和 OT2引脚没有使用，应保持开路。
表6. DS75LV地址引脚配置
PAGE
22
MAX34440 I2C TEMP SENSOR
DS75LV ADDRESS PIN CONFIGURATION
A2
A1
A0
6
MAX34440 Internal
—
—
—
7
DS75LV (Address 0)
0
0
0
8
DS75LV (Address 1)
0
0
1
9
DS75LV (Address 2)
0
1
0
10
DS75LV (Address 3)
0
1
1
11
MAX6695 (Local Sensor)
—
—
—
12
MAX6695 (Remote Diode 1)
—
—
—
13
MAX6695 (Remote Diode 2)
—
—
—
PMBus 6通道电源管理器
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 6 路电源和 8 个温度传感器。发送数据 0 至13 的 PAGE 命令选择受控于表1所有
PMBus 命令的电源、温度传感器。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。
表7. 页命令
PAGE (DEC)
ASSOCIATED CONTROL
0
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
Power Supply Connected to ADC 5
6
Internal Temperature Sensor
7
External DS75LV Temperature Sensor with Address 0
8
External DS75LV Temperature Sensor with Address 1
9
External DS75LV Temperature Sensor with Address 2
10
External DS75LV Temperature Sensor with Address 3
11
External MAX6695 Local Temperature Sensor
12
External MAX6695 Remote Diode 1 Temperature Sensor
13
14 to 254
255
External MAX6695 Remote Diode 2 Temperature Sensor
Reserved
Applies to All Pages
23
MAX34440
PMBus命令
MAX34440
PMBus 6通道电源管理器
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 8 和表 9。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 8 和表 9 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过压、过流和欠压报警
和故障，不进行报告。表 8 和表 9 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 8 和表 9 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。
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8. 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)
Margin Low (Act On Any Fault)
98h
On
A4h
On
Margin High (Ignore All Faults)
A8h
On
Margin High (Act On Any Fault)
注：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9. 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。
24
PMBus 6通道电源管理器
表10. 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11给出了WRITE_PROTECT的信息内容。
表11. 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。
25
MAX34440
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10 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。
MAX34440
PMBus 6通道电源管理器
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。
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12 给出了信息内容的说明。
表12. 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。
26
PMBus 6通道电源管理器
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13. VOUT_SCALE_MONITOR
NOMINAL VOLTAGE LEVEL NOMINAL ADC INPUT VOLTAGE
MONITORED (V)
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
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。
27
MAX34440
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
MAX34440
PMBus 6通道电源管理器
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。该报警值在输出电压首次达到所设置的 VOUT_UV_FAULT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。该故障在输出电压首次达到所设置的VOUT_UV_
FAULT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。
28
PMBus 6通道电源管理器
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14. 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。
29
MAX34440
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。
MAX34440
PMBus 6通道电源管理器
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。
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1. 电源排序
30
POWER_GOOD_OFF
PMBus 6通道电源管理器
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。
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15. TON_MAX_FAULT_LIMIT
TON_MAX_FAULT_LIMIT VALUE
8000h to FFFFh
0000h
0001h to 7FFFh
DEVICE RESPONSE (FOR THE ASSOCIATED PAGE)
Negative values are invalid.
Channel off (PSEN remains deasserted with no monitoring).
Channel on and sequencing enabled.
注：TON_MAX_FAULT_LIMIT 应设置为大于5ms。
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。
31
MAX34440
POWER_GOOD_OFF (5Fh)
POWER_GOOD_OFF 命令设置在 PG 输出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，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、POWER_GOOD# 和 STATUS_MFR_SPECIFIC位置位。
3)将 STATUS_MFR_SPECIFIC 中的 POWER_GOOD# 位置位。
MAX34440
PMBus 6通道电源管理器
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16 给出了STATUS_BYTE
的信息内容，该命令为只读命令。
表16. 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.
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17 所示为 STATUS_WORD 消息内容。
表17. 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#
10:6
0
5
VOUT_OV
An overvoltage fault has occurred.
4
IOUT_OC
An overcurrent fault has occurred.
3
0
2
TEMPERATURE
1
0
32
MEANING
CML
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.
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.
PMBus 6通道电源管理器
表18. 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19。
表19. STATUS_CML
BIT
BIT NAME
7
COMM_FAULT
An invalid or unsupported command has been received.
An invalid or unsupported data has been received.
6
DATA_FAULT
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.
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 20。
表 20. 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。
33
MAX34440
STATUS_VOUT (7Ah)
STATUS_VOUT命令返回1个字节的信息，内容说明请参见表18。
MAX34440
PMBus 6通道电源管理器
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。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。
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51h(Q)。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10101010。
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10101010。
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10101010。
34
PMBus 6通道电源管理器
表 21. MFR_MODE
BIT
BIT NAME
MEANING
15
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
FORCE_NV_FAULT_LOG
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
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
CLEAR_NV_FAULT_LOG
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
12
0
11
SOFT_RESET
10:9
8
PGTIME[1:0]
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
This bit always returns a 0.
7
PSEN_PP_OD
Applies to all PSEN outputs.
0 = PSEN push-pull output.
1 = PSEN open-drain output.
6
PSEN_HI_LO
Applies to all PSEN outputs.
0 = PSEN active low.
1 = PSEN active high.
5:0
0
These bits always return a 0.
注：VDD 必须大于2.9V，器件才能清除或将数据记录至 MFR_NV_FAULT_LOG。电源排序时，不应修改 MFR_MODE。
35
MAX34440
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 21。
MAX34440
PMBus 6通道电源管理器
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 22。
表 22. MFR_FAULT_RESPONSE
BIT
BIT NAME
MEANING
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
UV_OV_FILTER
12:10
9:8
7:6
5:4
0
0 = Fault on first voltage sample excursion occurrence.
1 = Requires two consecutive voltage sample excursions before a fault is
declared and action is taken.
These bits always return a 0.
IOUT_OC_FAULT_LIMIT_RESPONSE[1:0] See Table 23.
OT_FAULT_LIMIT_RESPONSE[1:0]
See Table 23 (see Notes 1 and 2).
TON_MAX_FAULT_LIMIT_RESPONSE[1:0] See Table 23.
3:2
VOUT_UV_FAULT_LIMIT_RESPONSE[1:0] See Table 23.
1:0
VOUT_OV_FAULT_LIMIT_RESPONSE[1:0] See Table 23.
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故障的响应方式进行响应。
注 3： 对电源故障的响应由故障通道的 MFR_FAULT_RESPONSE 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。
36
PMBus 6通道电源管理器
RESPONSE
SETTING
[1:0]
11
10
01
00
MAX34440
表 23. MFR_FAULT_RESPONSE编码
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.
•
•
•
Set the corresponding fault bit in the appropriate status register.
Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1.
If GLOBAL = 1, assert the FAULT output until faults on all GLOBAL supplies clear and MFR_FAULT_RETRY
expires.
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.
•
•
•
•
•
Set the corresponding fault bit in the appropriate status register.
Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1.
If GLOBAL = 1, assert the FAULT output until power supplies are restarted by the user.
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.
•
•
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、电流和温度的最新工作状态，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 24 的说明。
37
MAX34440
PMBus 6通道电源管理器
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
FAULT OCCURENCE
MFR_NV_FAULT_LOG
FAULT LOG INDEX 2
(255 BYTES)
FAULT LOG INDEX 14
(255 BYTES)
图2.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2。
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 24. 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
38
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 Pages 4/5
STATUS_MFR_SPECIFIC Pages 0/1
STATUS_MFR_SPECIFIC Pages 2/3
STATUS_MFR_SPECIFIC Pages 4/5
STATUS_MFR_SPECIFIC Pages 6/7
STATUS_MFR_SPECIFIC Pages 8/9
STATUS_MFR_SPECIFIC Pages 10/11
STATUS_MFR_SPECIFIC Pages 12/13
MFR_VOUT_PEAK Page 0
MFR_VOUT_PEAK Page 1
MFR_VOUT_PEAK Page 2
MFR_VOUT_PEAK Page 3
MFR_VOUT_PEAK Page 4
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
READ_VOUT Index = 3, Page 5
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
READ_VOUT Index = 4, Page 5
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
READ_VOUT Index = 5, Page 5
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 6通道电源管理器
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 5
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
MFR_IOUT_PEAK Page 5
MFR_TEMPERATURE_PEAK Page 6
MFR_TEMPERATURE_PEAK Page 7
MFR_TEMPERATURE_PEAK Page 8
MFR_TEMPERATURE_PEAK Page 9
MFR_TEMPERATURE_PEAK Page 10
MFR_TEMPERATURE_PEAK Page 11
MFR_TEMPERATURE_PEAK Page 12
MFR_TEMPERATURE_PEAK Page 13
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
MFR_VOUT_MIN Page 5
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
READ_VOUT Index = 0, Page 5
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
READ_VOUT Index = 1, Page 5
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
READ_VOUT Index = 2, Page 5
READ_VOUT Index = 3, Page 0
READ_VOUT Index = 3, Page 1
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
MAX34440
表 24. MFR_NV_FAULT_LOG (续)
PARAMETER
READ_VOUT Index = 6, Page 5
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
READ_VOUT Index = 7, Page 5
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
READ_IOUT Index = 0, Page 5
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
READ_IOUT Index = 1, Page 5
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
READ_IOUT Index = 2, Page 5
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
READ_IOUT Index = 3, Page 5
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_TEMPERATURE_1 Page 12
READ_TEMPERATURE_1 Page 13
LOG_VALID (see note)
注：如果故障记录包含有效数据，LOG_VALID 被设为 DDh。
39
MAX34440
PMBus 6通道电源管理器
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 25。
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 25. MFR_MARGIN_CONFIG
40
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 6通道电源管理器
表 26. MFR_TEMP_SENSOR_CONFIG
BIT
BIT NAME
15
ENABLE
14:0
0
MEANING
Clearing and setting this bit reinitializes the temperature sensor.
0 = Temperature sensor disabled.
1 = Temperature sensor enabled.
These bits always return a 0.
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。
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 VDD，以实现逻辑高电平。
PSEN0至 PSEN5 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 )。
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)。
不要将其它电路连接至这两个引脚。
41
MAX34440
MFR_TEMP_SENSOR_CONFIG (F0h)
MFR_TEMP_SENSOR_CONFIG 命令用于配置温度传感器。表 26 中介绍了MFR_TEMP_SENSOR_CONFIG 命令。
MAX34440
PMBus 6通道电源管理器
典型工作电路
INPUT VOLTAGE
IN
MAX6695
TWO REMOTE
AND ONE LOCAL
OUT
POWER
SUPPLY
MAX9938
CURRENT-SENSE
AMPLIFIER
TRIM
EN
LOAD
SPDT
MUX
6 CHANNELS
PSEN0
PWM0
RS-0
RS+0
MSDA
DS75LV
I2C TEMP
SENSOR
MSCL
+3.3V
VSS
HOST
INTERFACE
FROM
MUXSEL
PSEN1
PWM1
RS-1
RS+1
VDD
SDA
SCL
OPTIONAL
SUPPORT
FOR CURRENT
MONITORING
MAX34440
RST
ALERT
FAULT
A0/MUXSEL
A1/PG
PSEN2
PWM2
RS-2
RS+2
PSEN3
PWM3
RS-3
RS+3
PSEN4
PWM4
RS-4
RS+4
REG25
PSEN5
PWM5
RS-5
RS+5
REG18
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。
42
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 6通道电源管理器
修订号
修订日期
0
9/10
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
43
Maxim 是 MaximIntegratedProducts,Inc.的注册商标。
MAX34440
修订历史
19-5527; Rev 1; 1/12
PMBus 6-Channel Power-Supply Manager
The MAX34440 is a complex system monitor that can
manage up to six power supplies. 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
power-supply output voltage up or down to a userprogrammable 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 powersupply 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.
Applications
Network Switches/Routers
Base Stations
Servers
Smart Grid Network Systems
Industrial Controls
Features
S6 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
SSupports Up to Eight Temperature Sensors
Two Remote Diode Temperature Sensors_
Five Local Temperature Sensors_
One Internal Temperature Sensor_
Fault Detection on All Temp Sensors
SPMBus™-Compliant Command Interface
SI2C/SMBus-Compatible Serial Bus with Bus
Timeout Function
SOn-Board Nonvolatile Fault Logging and Default
Configuration Setting
SNo External Clocking Required
S+3.3V Supply Voltage
Ordering Information
TEMP RANGE
PIN-PACKAGE
MAX34440ETL+
PART
-40NC to +85NC
40 TQFN-EP*
MAX34440ETL+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.
MAX34440
General Description
MAX34440
PMBus 6-Channel Power-Supply Manager
TABLE OF CONTENTS
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
I2C/SMBus Interface Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Sending a DIRECT Format Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Fault Management and Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
System Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Temperature Sensor Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2
PMBus 6-Channel Power-Supply Manager
PMBus Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
PAGE (00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
OPERATION (01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
ON_OFF_CONFIG (02h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
CLEAR_FAULTS (03h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
WRITE_PROTECT (10h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
STORE_DEFAULT_ALL (11h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
RESTORE_DEFAULT_ALL (12h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
CAPABILITY (19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
VOUT_MODE (20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
VOUT_MARGIN_HIGH (25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
VOUT_MARGIN_LOW (26h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
VOUT_SCALE_MONITOR (2Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
IOUT_CAL_GAIN (38h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
VOUT_OV_FAULT_LIMIT (40h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
VOUT_OV_WARN_LIMIT (42h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
VOUT_UV_WARN_LIMIT (43h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
VOUT_UV_FAULT_LIMIT (44h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
IOUT_OC_WARN_LIMIT (46h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
IOUT_OC_FAULT_LIMIT (4Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
OT_FAULT_LIMIT (4Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
OT_WARN_LIMIT (51h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
POWER_GOOD_ON (5Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
POWER_GOOD_OFF (5Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
TON_DELAY (60h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
TON_MAX_FAULT_LIMIT (62h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
TOFF_DELAY (64h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
STATUS_BYTE (78h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
STATUS_WORD (79h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
STATUS_VOUT (7Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
STATUS_CML (7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
STATUS_MFR_SPECIFIC (80h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
READ_VOUT (8Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
READ_IOUT (8Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
READ_TEMPERATURE_1 (8Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
PMBUS_REVISION (98h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
MFR_ID (99h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3
MAX34440
TABLE OF CONTENTS (continued)
MAX34440
PMBus 6-Channel Power-Supply Manager
TABLE OF CONTENTS (continued)
MFR_MODEL (9Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
MFR_REVISION (9Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
MFR_LOCATION (9Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
MFR_DATE (9Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
MFR_SERIAL (9Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
MFR_MODE (D1h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
MFR_VOUT_PEAK (D4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
MFR_IOUT_PEAK (D5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
MFR_TEMPERATURE_PEAK (D6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
MFR_VOUT_MIN (D7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
MFR_FAULT_RESPONSE (D9h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
MFR_FAULT_RETRY (DAh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
MFR_NV_FAULT_LOG (DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
MFR_TIME_COUNT (DDh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
MFR_MARGIN_CONFIG (E0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
MFR_TEMP_SENSOR_CONFIG (F0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Power-Supply Decoupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Open-Drain Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Typical Operating Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4
PMBus 6-Channel Power-Supply Manager
Figure 1. Power-Supply Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Figure 2. MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
LIST OF TABLES
Table 1. PMBus Command Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Table 2. PMBus/SMBus Serial-Port Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 3. PMBus Command Code Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 4. Coefficients for DIRECT Format Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 5. Device Parametric Monitoring States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 6. DS75LV Address Pin Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 7. Page Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 8. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 9. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 10. ON_OFF_CONFIG (02h) Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 11. WRITE_PROTECT Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 12. CAPABILITY Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 13. VOUT_SCALE_MONITOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 14. IOUT_OC_FAULT_LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 15. TON_MAX_FAULT_LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 16. STATUS_BYTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 17. STATUS_WORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 18. STATUS_VOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 19. STATUS_CML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 20. STATUS_MFR_SPECIFIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 21. MFR_MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 22. MFR_FAULT_RESPONSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 23. MFR_FAULT_RESPONSE Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 24. MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 25. MFR_MARGIN_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 26. MFR_TEMP_SENSOR_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5
MAX34440
LIST OF FIGURES
MAX34440
PMBus 6-Channel Power-Supply Manager
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 6-Channel Power-Supply Manager
(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
Bits
15
MI
(Note 4)
Q8
VOFFSET
-3
LSB
LSB
Q2
TA = -40NC to +85NC
V
FV
12
ADC Integral Nonlinearity
ADC Offset
MIN
+3
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
Temperature Sample Rate
1000
ms
12
ms
Device Startup Time
Measurement from POR until monitoring
begins
PWM Frequency
Power supply
62.5
kHz
PWM Resolution
Power supply
6
Bits
7
MAX34440
DC ELECTRICAL CHARACTERISTICS (continued)
MAX34440
PMBus 6-Channel Power-Supply Manager
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 6-Channel Power-Supply Manager
(TA = +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. TEMPERATURE
2.5
2.5
2.4
IDD (mA)
2.4
IDD (mA)
MAX34440 toc02
2.6
MAX34440 toc01
2.6
2.3
VDD = 3.3V
2.3
TA = +25°C
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 NONVOLATILE LOG WRITE
(TA = +25°C, VDD = 3.3V)
MAX34440 toc03
MAX34440 toc04
C1 = PSEN0
0V
C3 = PWM0
0V
1mA/div
1V/div
C2 = VDD
0V
0A
1ms/div
2ms/div
FILTERED MARGINING VOLTAGE
vs. TIME DURING MARGIN UP
MAX34440 toc05
200mV/div
0V
100ms/div
9
MAX34440
Typical Operating Characteristics
PMBus 6-Channel Power-Supply Manager
VSS
REG18
PSEN3
PWM2
PWM1
PSEN2
PSEN1
PWM0
TOP VIEW
REG25
PSEN0
MAX34440
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 PSEN5
CONTROL 35
16 PWM5
MAX34440
VSS 36
15 MSCL
A1/PG 37
14 MSDA
ALERT 38
RS-5 39
13 RST
EP
+
12 RS-2
11 RS+2
5
6
VSS
RS+4
RS-3
RS+3
RS+0
7
8
9
10
RS-1
4
VDD
3
RS-0
2
RS+1
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
PWM Margin Output #5. High impedance when the margining is disabled. A 100% duty cycle implies
this pin is continuously high.
17
PSEN5
Power-Supply Enable Output #5. Programmable through MFR_MODE for either active high or active
low and either open drain or CMOS push-pull.
Reset Active-Low Input
PMBus 6-Channel Power-Supply Manager
PIN
NAME
FUNCTION
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.
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.
37
A1/PG
SMBus Address 1 Input/Power-Good 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 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.
38
ALERT
Active-Low, Open-Drain Alert Output
11
MAX34440
Pin Description (continued)
Pin Description (continued)
PIN
NAME
39
RS-5
Ground Reference for ADC5 Voltage Measurement
FUNCTION
40
RS+5
Power-Supply ADC Voltage-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.
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
MSDA
MSCL
SDA
SCL
RST
ALERT
FAULT
CONTROL
A0/MUXSEL
A1/PG
SMBus
MASTER
INTERFACE
PSEN1
PSEN2
PSEN3
PSEN4
PSEN5
SMBus
SLAVE
INTERFACE
ADC
SYSTEM
CONTROL
SIGNALS
MAX34440
12
16-BIT
MAXQ
RISC CORE
POWERSUPPLY
OUTPUT
ENABLES
MUX
MAX34440
PMBus 6-Channel Power-Supply Manager
RAM
FLASH
TEMP
SENSOR
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 6-Channel Power-Supply Manager
+3.3V
ALERT
HOST
INTERFACE
CLOCK
DATA
CONTROL
RST
SDA
SCL
RST
ALERT
MAX34440
#0
FAULT
CONTROL
A1/PG
A0/MUXSEL
+3.3V
SDA
SCL
RST
ALERT
FAULT
MAX34440
#1
CONTROL
A1/PG
A0/MUXSEL
ADDITIONAL DEVICES
13
MAX34440
Multiple Device Connection Diagram
MAX34440
PMBus 6-Channel Power-Supply Manager
Detailed Description
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.
The MAX34440 is a highly integrated system monitor
based upon a 16-bit MAXQM microcontroller with factory-programmed functionality to monitor up to six power
supplies. The device provides power-supply closed-loop
control, and local/remote thermal-sensing facilities.
Thermal monitoring can be accomplished using up to
eight temperature sensors, including an on-chip thermal sensor, four DS75LV digital thermometers, and a
MAX6695 dual remote/local thermal temperature sensor.
Communication with the DS75LV and MAX6695 temperature sensors is conducted through a dedicated I2C/
SMBus interface.
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 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 MAX34440
devices to reside on the system’s I/O bus.
Table 1. PMBus Command Codes
CODE
COMMAND NAME
TYPE
PAGE
0–5
PAGE
6–13
PAGE
255
(NOTE 1)
FLASH
STORED
(NOTE 2)
DEFAULT
VALUE
(NOTE 2)
00h
00h
PAGE
R/W Byte
R/W
R/W
R/W
1
N
01h
OPERATION
R/W Byte
R/W
—
W
1
N
00h
02h
ON_OFF_CONFIG
R/W Byte
R/W
R/W
R/W
1
Y
1Ah
03h
CLEAR_FAULTS
Send Byte
W
W
W
0
N
—
10h
WRITE_PROTECT
R/W Byte
R/W
R/W
R/W
1
N
00h
11h
STORE_DEFAULT_ALL
Send Byte
W
W
W
0
N
—
12h
RESTORE_DEFAULT_ALL
Send Byte
W
W
W
0
N
—
19h
CAPABILITY
Read Byte
R
R
R
1
N
00h/10h
20h
VOUT_MODE
Read Byte
R
R
R
1
FIXED
40h
25h
VOUT_MARGIN_HIGH
R/W Word
R/W
—
—
2
Y
0000h
26h
VOUT_MARGIN_LOW
R/W Word
R/W
—
—
2
Y
0000h
2Ah
VOUT_SCALE_MONITOR
R/W Word
R/W
—
—
2
Y
7FFFh
38h
IOUT_CAL_GAIN
R/W Word
R/W
—
—
2
Y
0000h
40h
VOUT_OV_FAULT_LIMIT
R/W Word
R/W
—
—
2
Y
7FFFh
42h
VOUT_OV_WARN_LIMIT
R/W Word
R/W
—
—
2
Y
7FFFh
43h
VOUT_UV_WARN_LIMIT
R/W Word
R/W
—
—
2
Y
0000h
0000h
44h
VOUT_UV_FAULT_LIMIT
R/W Word
R/W
—
—
2
Y
46h
IOUT_OC_WARN_LIMIT
R/W Word
R/W
—
—
2
Y
7FFFh
4Ah
IOUT_OC_FAULT_LIMIT
R/W Word
R/W
—
—
2
Y
0000h
4Fh
OT_FAULT_LIMIT
R/W Word
—
R/W
—
2
Y
7FFFh
7FFFh
51h
OT_WARN_LIMIT
R/W Word
—
R/W
—
2
Y
5Eh
POWER_GOOD_ON
R/W Word
R/W
—
—
2
Y
0000h
5Fh
POWER_GOOD_OFF
R/W Word
R/W
—
—
2
Y
0000h
MAXQ is a registered trademark of Maxim Integrated
Products, Inc.
14
NO. OF
BYTES
PMBus 6-Channel Power-Supply Manager
CODE
COMMAND NAME
TYPE
PAGE
0–5
PAGE
6–13
PAGE
255
(NOTE 1)
NO. OF
BYTES
FLASH
STORED
(NOTE 2)
DEFAULT
VALUE
(NOTE 2)
60h
TON_DELAY
R/W Word
R/W
—
—
2
Y
0000h
62h
TON_MAX_FAULT_LIMIT
R/W Word
R/W
—
—
2
Y
0000h
64h
TOFF_DELAY
R/W Word
R/W
—
—
2
Y
0000h
78h
STATUS_BYTE
Read Byte
R
R
R
1
N
00h
79h
STATUS_WORD
Read Word
R
R
R
2
N
0000h
7Ah
STATUS_VOUT
Read Byte
R
—
—
1
N
00h
7Eh
STATUS_CML
Read Byte
R
R
R
1
N
00h
80h
STATUS_MFR_SPECIFIC
Read Byte
R
R
—
1
N
00h
8Bh
READ_VOUT
Read Word
R
—
—
2
N
0000h
8Ch
READ_IOUT
Read Word
R
—
—
2
N
0000h
8Dh
READ_TEMPERATURE_1
Read Word
—
R
—
2
N
0000h
98h
PMBUS_REVISION
Read Byte
R
R
R
1
FIXED
11h
99h
MFR_ID
Read Byte
R
R
R
1
FIXED
4Dh
9Ah
MFR_MODEL
Read Byte
R
R
R
1
FIXED
51h
9Bh
MFR_REVISION
Read Word
R
R
R
2
FIXED
3030h
9Ch
MFR_LOCATION
Block R/W
R/W
R/W
R/W
8
Y
(Note 3)
9Dh
MFR_DATE
Block R/W
R/W
R/W
R/W
8
Y
(Note 3)
9Eh
MFR_SERIAL
Block R/W
R/W
R/W
R/W
8
Y
(Note 3)
D1h
MFR_MODE
R/W Word
R/W
R/W
R/W
2
Y
0000h
D4h
MFR_VOUT_PEAK
R/W Word
R/W
—
—
2
N
0000h
0000h
D5h
MFR_IOUT_PEAK
R/W Word
R/W
—
—
2
N
D6h
MFR_TEMPERATURE_PEAK
R/W Word
—
R/W
—
2
N
8000h
D7h
MFR_VOUT_MIN
R/W Word
R/W
—
—
2
N
7FFFh
D9h
MFR_FAULT_RESPONSE
R/W Word
R/W
—
—
2
Y
0000h
DAh
MFR_FAULT_RETRY
R/W Word
R/W
R/W
R/W
2
Y
0000h
DCh
MFR_NV_FAULT_LOG
Block Read
R
R
R
255
Y
(Note 4)
DDh
MFR_TIME_COUNT
Block Read
R
R
R
4
N
(Note 5)
E0h
MFR_MARGIN_CONFIG
R/W Word
R/W
—
—
2
Y
0000h
F0h
MFR_TEMP_SENSOR_CONFIG
R/W Word
—
R/W
—
2
Y
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
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.
Note 3: The factory-set default value for this 8-byte block is 3130313031303130h.
Note 4: The factory-set default value for the complete block of the MFR_NV_FAULT_LOG is FFh.
Note 5: The power-on reset value for this 4-byte block is 00000000h.
15
MAX34440
Table 1. PMBus Command Codes (continued)
MAX34440
PMBus 6-Channel Power-Supply Manager
Table 2. PMBus/SMBus Serial-Port Address
7-BIT SLAVE
ADDRESS
A1
A0
100kI to VSS
100kI to VSS
100kI to VDD
100kI to VDD
Address Select
On device power-up, the device samples the A0 and A1
pins to determine the PMBus/SMBus serial-port address.
SMBus/PMBus Operation
1101 010 (D4h)
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. Data is sent most
significant bit (MSB) first.
1101 011 (D6h)
100kI to VSS
1101 100 (D8h)
100kI to VDD
1101 101 (DAh)
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
WRITE WORD FORMAT
1
7
1
1
8
1
8
1
8
1
1
S
SLAVE
ADDRESS
W
A
COMMAND
CODE
A
DATA BYTE
LOW
A
DATA BYTE
HIGH
A
P
WRITE BYTE FORMAT
1
7
1
1
8
1
8
1
1
S
SLAVE
ADDRESS
W
A
COMMAND
CODE
A
DATA BYTE
A
P
1
8
1
1
A
COMMAND
CODE
A
P
SEND BYTE FORMAT
16
1
7
S
SLAVE
ADDRESS
1
W
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 6-Channel Power-Supply Manager
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
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
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
1
8
1
1
A
DATA BYTE
HIGH
A
P
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
MAX34440
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
MAX34440
PMBus 6-Channel Power-Supply Manager
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 6-Channel Power-Supply Manager
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
(tTO), 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 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 MAX34440 operating
in conjunction with a power supply. While the command
can call for turning on or turning off the PMBus device,
the MAX34440 always remains on to continue communicating with the PMBus master, and the MAX34440
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.
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 MAX34440—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.
19
MAX34440
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:
MAX34440
PMBus 6-Channel Power-Supply Manager
Table 3. PMBus Command Code Coefficients
PARAMETER
Voltage
Voltage Scaling
Current
Current Scaling
Temperature
Timing
COMMANDS
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
VOUT_SCALE_MONITOR
IOUT_OC_WARN_LIMIT
IOUT_OC_FAULT_LIMIT
READ_IOUT
MFR_IOUT_PEAK
IOUT_CAL_GAIN
OT_FAULT_LIMIT
OT_WARN_LIMIT
READ_TEMPERATURE_1
MFR_TEMPERATURE_PEAK
TON_DELAY
TON_MAX_FAULT_LIMIT
TOFF_DELAY
MFR_FAULT_RETRY
Sending a DIRECT Format Value
UNITS
RESOLUTION
MAX
m
b
R
mV
1
32,767
1
0
0
—
1/32,767
1
32,767
0
0
mA
1
32,767
1
0
0
mI
0.1
3276.7
1
0
1
NC
0.01
327.67
1
0
2
ms
1
32,767
1
0
0
To send a value, the host must use the below equation
to solve for Y:
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:
Y = (mX + b) x 10R
Y = (1 x 3465 + 0) x 100 = 3465 (decimal) = 0D89h (hex)
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.
Conversely, if the host received a value of 0D89h on a
READ_VOUT command, this is equivalent to:
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.
Table 4. Coefficients for DIRECT Format
Value
COMMAND
CODE
20
COMMAND NAME
m
b
R
25h
VOUT_MARGIN_HIGH
1
0
0
8Bh
READ_VOUT
1
0
0
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.
PMBus 6-Channel Power-Supply Manager
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.
• Bias power to the device is removed and then reapplied.
One or more latched-off power supplies is only restarted
when one of the following occurs:
• The output is commanded through the CONTROL
pin, the OPERATION command, or the combined
action of the CONTROL pin and OPERATION command to turn off and then turn back on.
• 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 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).
Table 5. Device Parametric Monitoring States
PARAMETER
Overvoltage
Undervoltage
Overcurrent
Power-Up Time
Overtemperature
REQUIRED CONDITIONS FOR ACTIVE MONITORING
Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h)
•
•
•
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
• Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h)
• Current Monitoring Enabled (IOUT_OC_FAULT_LIMIT ≠ 0000h)
Power Supply Enabled (TON_MAX_FAULT_LIMIT ≠ 0000h)
Temp Sensor Enabled (ENABLE in MFR_TEMP_SENSOR_CONFIG = 1)
ACTION DURING A FAULT
Continue Monitoring
Stop Monitoring While the Power
Supply is Off
Continue Monitoring
Monitor Only During Power-On
Continue Monitoring
21
MAX34440
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.
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.
MAX34440
PMBus 6-Channel Power-Supply Manager
Temperature Sensor Operation
The device can monitor up to eight different temperature
sensors, seven external sensors plus its own internal
temperature sensor. The external temperature sensors
are all connected in parallel to the master I2C port
(MSDA and MSCL pins). The device can support up to
four DS75LV devices plus one MAX6695 device. Each
of the enabled temperature sensors is measured once
a second. The internal temperature sensor is 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
either an open or short across the diode. 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. Reading disabled temperature sensors returns a fixed value of 0000h.
The device can control up to four DS75LV digital temperature sensors. The A0, A1, and A2 pins on the DS75LV
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.
The device can control one MAX6695, which consists of
one local temperature sensor and two remote diode temperature sensors. Each of the temperature sensors can
be reinitialized by disabling and re-enabling the sensor
through MFR_TEMP_SENSOR_CONFIG. The valid range
for the MAX6695 temperature sensor is -40°C to +125°C.
The page assignment is shown in Table 6. The ALERT,
OT1, and OT2 pins on the MAX6695 are not used and
should be left open circuit.
Table 6. DS75LV Address Pin Configurations
PAGE
22
MAX34440 I2C TEMP SENSOR
DS75LV ADDRESS PIN CONFIGURATION
A2
A1
A0
6
MAX34440 Internal
—
—
—
7
DS75LV (Address 0)
0
0
0
8
DS75LV (Address 1)
0
0
1
9
DS75LV (Address 2)
0
1
0
10
DS75LV (Address 3)
0
1
1
11
MAX6695 (Local Sensor)
—
—
—
12
MAX6695 (Remote Diode 1)
—
—
—
13
MAX6695 (Remote Diode 2)
—
—
—
PMBus 6-Channel Power-Supply Manager
A summary of the PMBus commands supported by the device are described in the following sections.
PAGE (00h)
The device can control up to six power supplies and up to eight temperature sensors using one PMBus (I2C) address.
Send the PAGE command with data 0 to 13 to select which power supply or which temperature sensor 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.
Table 7. Page Commands
PAGE (DEC)
ASSOCIATED CONTROL
0
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
Power Supply Connected to ADC 5
6
Internal Temperature Sensor
7
External DS75LV Temperature Sensor with Address 0
8
External DS75LV Temperature Sensor with Address 1
9
External DS75LV Temperature Sensor with Address 2
10
External DS75LV Temperature Sensor with Address 3
11
External MAX6695 Local Temperature Sensor
12
External MAX6695 Remote Diode 1 Temperature Sensor
13
External MAX6695 Remote Diode 2 Temperature Sensor
14 to 254
255
Reserved
Applies to All Pages
23
MAX34440
PMBus Commands
MAX34440
PMBus 6-Channel Power-Supply Manager
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 8 and 9. 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 8 and 9, “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 8 and 9 is an invalid command. If the device receives a data byte that is not listed in Tables 8 and 9, 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.
USER NOTE: All power supplies tagged as GLOBAL supplies (see MFR_FAULT_RESPONSE) should be turned
on and off at the same time.
Table 8. 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)
98h
On
Margin Low (Act On Any Fault)
A4h
On
Margin High (Ignore All Faults)
A8h
On
Margin High (Act On Any Fault)
Note: The VOUT of all enabled channels must exceed POWER_GOOD_ON for margining to begin.
Table 9. 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.
24
PMBus 6-Channel Power-Supply Manager
Table 10. 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 11.
Table 11. 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.
25
MAX34440
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 10 describes the ON_OFF_CONFIG message content. The host should not modify ON_OFF_CONFIG
while the power supplies are active.
MAX34440
PMBus 6-Channel Power-Supply Manager
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. 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.
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. 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 the Table 12.
Table 12. 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).
26
PMBus 6-Channel Power-Supply Manager
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 13. 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.
27
MAX34440
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:
MAX34440
PMBus 6-Channel Power-Supply Manager
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).
28
PMBus 6-Channel Power-Supply Manager
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 14. 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).
29
MAX34440
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:
MAX34440
PMBus 6-Channel Power-Supply Manager
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 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 power-supply 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.
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 1. Power-Supply Sequencing
30
POWER_GOOD_OFF
PMBus 6-Channel Power-Supply Manager
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 STATUS_MFR_SPECIFIC bits in STATUS_WORD.
3) Sets the POWER_GOOD# bit in STATUS_MFR_SPECIFIC.
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.
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 15. TON_MAX_FAULT_LIMIT
TON_MAX_FAULT_LIMIT VALUE
8000h to FFFFh
0000h
0001h to 7FFFh
DEVICE RESPONSE (FOR THE ASSOCIATED PAGE)
Negative values are invalid.
Channel off (PSEN remains deasserted with no monitoring).
Channel on and sequencing enabled.
Note: TON_MAX_FAULT_LIMIT should be set higher than 5ms.
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.
31
MAX34440
POWER_GOOD_OFF (5Fh)
The POWER_GOOD_OFF command sets the value of the output voltage that causes the PG output 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.
MAX34440
PMBus 6-Channel Power-Supply Manager
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 16. This command is read-only.
Table 16. 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.
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 17 describes the STATUS_WORD message content.
Table 17. STATUS_WORD
BIT
BIT NAME
15
VOUT
14
IOUT
13
0
12
MFR
11
POWER_GOOD#
10:6
0
5
VOUT_OV
4
IOUT_OC
3
0
2
TEMPERATURE
1
CML
0
32
MEANING
An output voltage fault or warning or TON_MAX_FAULT has occurred.
An overcurrent fault or warning has occurred.
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.
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.
PMBus 6-Channel Power-Supply Manager
Table 18. 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 19.
Table 19. STATUS_CML
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.
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 20.
Table 20. 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.
33
MAX34440
STATUS_VOUT (7Ah)
The STATUS_VOUT command returns 1 byte of information with contents as described in Table 18.
MAX34440
PMBus 6-Channel Power-Supply Manager
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.
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.
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 51h (Q). 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 3030h (00). 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 10101010.
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 10101010.
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 10101010.
34
PMBus 6-Channel Power-Supply Manager
Table 21. MFR_MODE
BIT
BIT NAME
MEANING
15
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
FORCE_NV_FAULT_LOG
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
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
CLEAR_NV_FAULT_LOG
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
12
0
11
SOFT_RESET
10:9
PGTIME[1:0]
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
8
0
This bit always returns a 0.
7
PSEN_PP_OD
Applies to all PSEN outputs.
0 = PSEN push-pull output.
1 = PSEN open-drain output.
6
PSEN_HI_LO
Applies to all PSEN outputs.
0 = PSEN active low.
1 = PSEN active high.
5:0
0
These bits always return a 0.
Note: VDD must be above 2.9V for the device to clear or log data into MFR_NV_FAULT_LOG. MFR_MODE should not be changed
while power supplies are being sequenced.
35
MAX34440
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 21.
MAX34440
PMBus 6-Channel Power-Supply Manager
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 reports 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 22.
Table 22. 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
UV_OV_FILTER
12:10
0
9:8
7:6
MEANING
0 = Fault on first voltage sample excursion occurrence.
1 = Requires two consecutive voltage sample excursions before a fault is
declared and action is taken.
These bits always return a 0.
IOUT_OC_FAULT_LIMIT_RESPONSE[1:0] See Table 23.
OT_FAULT_LIMIT_RESPONSE[1:0]
See Table 23 (see Notes 1 and 2).
5:4
TON_MAX_FAULT_LIMIT_RESPONSE[1:0] See Table 23.
3:2
VOUT_UV_FAULT_LIMIT_RESPONSE[1:0] See Table 23.
1:0
VOUT_OV_FAULT_LIMIT_RESPONSE[1:0] See Table 23.
Note 1: All enabled temperature sensor faults are logically ORed together.
Note 2: Temperature 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 fault based upon the programmed response for the particular supply.
Note 3: The fault response for a power-supply fault is determined by MFR_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.
36
PMBus 6-Channel Power-Supply Manager
RESPONSE
SETTING
[1:0]
11
10
01
00
MAX34440
Table 23. MFR_FAULT_RESPONSE Codes
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.
•
•
•
Set the corresponding fault bit in the appropriate status register.
Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1.
If GLOBAL = 1, assert the FAULT output until faults on all GLOBAL supplies clear and MFR_FAULT_RETRY
expires.
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.
•
•
•
•
•
Set the corresponding fault bit in the appropriate status register.
Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1.
If GLOBAL = 1, assert the FAULT output until power supplies are restarted by the user.
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.
•
•
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, and temperature,
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 24.
37
MAX34440
PMBus 6-Channel Power-Supply Manager
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
FAULT OCCURENCE
MFR_NV_FAULT_LOG
FAULT LOG INDEX 2
(255 BYTES)
FAULT LOG INDEX 14
(255 BYTES)
Figure 2. 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 2.
USER NOTE: VDD must be above 2.9V for the device to clear or log data into MFR_NV_FAULT_LOG.
Table 24. 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
38
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 Pages 4/5
STATUS_MFR_SPECIFIC Pages 0/1
STATUS_MFR_SPECIFIC Pages 2/3
STATUS_MFR_SPECIFIC Pages 4/5
STATUS_MFR_SPECIFIC Pages 6/7
STATUS_MFR_SPECIFIC Pages 8/9
STATUS_MFR_SPECIFIC Pages 10/11
STATUS_MFR_SPECIFIC Pages 12/13
MFR_VOUT_PEAK Page 0
MFR_VOUT_PEAK Page 1
MFR_VOUT_PEAK Page 2
MFR_VOUT_PEAK Page 3
MFR_VOUT_PEAK Page 4
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
READ_VOUT Index = 3, Page 5
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
READ_VOUT Index = 4, Page 5
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
READ_VOUT Index = 5, Page 5
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 6-Channel Power-Supply Manager
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 5
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
MFR_IOUT_PEAK Page 5
MFR_TEMPERATURE_PEAK Page 6
MFR_TEMPERATURE_PEAK Page 7
MFR_TEMPERATURE_PEAK Page 8
MFR_TEMPERATURE_PEAK Page 9
MFR_TEMPERATURE_PEAK Page 10
MFR_TEMPERATURE_PEAK Page 11
MFR_TEMPERATURE_PEAK Page 12
MFR_TEMPERATURE_PEAK Page 13
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
MFR_VOUT_MIN Page 5
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
READ_VOUT Index = 0, Page 5
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
READ_VOUT Index = 1, Page 5
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
READ_VOUT Index = 2, Page 5
READ_VOUT Index = 3, Page 0
READ_VOUT Index = 3, Page 1
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
MAX34440
Table 24. MFR_NV_FAULT_LOG (continued)
PARAMETER
READ_VOUT Index = 6, Page 5
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
READ_VOUT Index = 7, Page 5
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
READ_IOUT Index = 0, Page 5
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
READ_IOUT Index = 1, Page 5
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
READ_IOUT Index = 2, Page 5
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
READ_IOUT Index = 3, Page 5
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_TEMPERATURE_1 Page 12
READ_TEMPERATURE_1 Page 13
LOG_VALID (see note)
Note: LOG_VALID is set to DDh if the fault log contains valid data.
39
MAX34440
PMBus 6-Channel Power-Supply Manager
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 25.
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 25. MFR_MARGIN_CONFIG
40
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 6-Channel Power-Supply Manager
Table 26. MFR_TEMP_SENSOR_CONFIG
BIT
BIT NAME
15
ENABLE
14:0
0
MEANING
Clearing and setting this bit reinitializes the temperature sensor.
0 = Temperature sensor disabled.
1 = Temperature sensor enabled.
These bits always return a 0.
Applications Information
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 PSEN5 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).
Do not connect other circuitry to either of these pins.
41
MAX34440
MFR_TEMP_SENSOR_CONFIG (F0h)
The MFR_TEMP_SENSOR_CONFIG command is used to configure the temperature sensors. Table 26 describes the
MFR_TEMP_SENSOR_CONFIG command.
PMBus 6-Channel Power-Supply Manager
MAX34440
Typical Operating Circuit
INPUT VOLTAGE
IN
MAX6695
TWO REMOTE
AND ONE LOCAL
OUT
POWER
SUPPLY
MAX9938
CURRENT-SENSE
AMPLIFIER
TRIM
EN
LOAD
SPDT
MUX
6 CHANNELS
PSEN0
PWM0
RS-0
RS+0
MSDA
DS75LV
I2C TEMP
SENSOR
MSCL
+3.3V
VSS
HOST
INTERFACE
FROM
MUXSEL
PSEN1
PWM1
RS-1
RS+1
VDD
SDA
SCL
OPTIONAL
SUPPORT
FOR CURRENT
MONITORING
MAX34440
RST
ALERT
FAULT
A0/MUXSEL
A1/PG
PSEN2
PWM2
RS-2
RS+2
PSEN3
PWM3
RS-3
RS+3
PSEN4
PWM4
RS-4
RS+4
REG25
PSEN5
PWM5
RS-5
RS+5
REG18
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.
42
PACKAGE TYPE
PACKAGE CODE
OUTLINE NO.
LAND PATTERN NO.
40 TQFN-EP
T4066+2
21-0141
90-0053
PMBus 6-Channel Power-Supply Manager
REVISION
NUMBER
REVISION
DATE
0
9/10
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
1
DESCRIPTION
PAGES
CHANGED
—
6, 7
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 43
Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX34440
Revision History