19-6083; Rev 0; 12/11 MAX34565 12V热插拔开关，提供TDFN封装 概述 MAX34565是 一 款 用 于12V电 源 的 热 插 拔 控 制 器。 该 器 件 为 完 备 的 集 成 方 案， 包 括 控 制12V电 源 通 断 所 需 的 MOSFET。带电插入期间，器件控制电源电压的上升速 度(dV/dt)并将电流限制在用户控制的范围内。该器件还 限制输出电压，以保护后续器件不受过压事件的影响。 MAX34565提供闭锁版本。 应用 Express® 特性 S为12V电源提供完备的热插拔控制功能 S集成功率MOSFET S无需大功率RSENSE电阻 S可调节电流限制 S可调整输出电压摆率 S热故障报警指示 S输出过压限制 RAID/硬盘驱动器 PCI/PCI 服务器 InfiniBandTM/SM S内置电荷泵 交换机/路由器 基站 S提供闭锁版器件 S内置热保护 定购信息在数据资料的最后给出。 +12V SUPPLY 功能框图 VCC UVLO 5V REG 68mΩ CHARGE PUMP LOAD +12V LOAD ILIM RILIM CURRENT LIMIT OVERVOLTAGE LIMIT MAX34565 GND VRAMP CVRAMP VOHT 17µA EN/FAULT 1.4V POR BLANKING THERMAL LIMIT VOLT THERMAL RESET PCI Express是PCI-SIG Corp.的注册服务标志。 InfiniBand是InfiniBand贸易协会的商标和服务标志。 相关型号以及配合该器件使用的推荐产品，请参见：china.maxim-ic.com/MAX34565.related。 ����������������������������������������������������������������� 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。 MAX34565 12V热插拔开关，提供TDFN封装 Absolute Maximum Ratings 12V Drain Current (TA = +25NC, 0.5sq in. pad)... 3.6A (continuous) Continuous Power Dissipation (TA = +70NC) TDFN (derate at 24.4mW/NC above +70NC)............1951.2mW Operating Junction Temperature...................... -40NC to +150NC Storage Temperature Range ........................... -55NC to +150NC Lead Temperature (soldering, 10s).................................+300NC Soldering Temperature (reflow).......................................+260NC (All voltages relative to GND.) Voltage Range on VCC Continuous..........................................................-0.3V to +18V 1ms.....................................................................-0.3V to +22V Voltage Range on ILIM, VRAMP............... -0.3V to (VCC + 0.3V), not to exceed +18V Voltage on EN/FAULT..............................................-0.3V to +6V 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 (TJ = -40NC to +150NC, unless otherwise noted.) PARAMETER SYMBOL VCC Voltage VCC RILIM Value RILIM EN/FAULT Low Level (LOAD Disabled) VOLT EN/FAULT High Level (LOAD Enabled) VOHT CONDITIONS (Notes 1, 2) MIN TYP MAX 9 12 13.2 V 30 I 0.80 V 12 3.3 UNITS V Electrical Characteristics (VCC = 12V, TJ = +25NC, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Current ICC 1.6 2.25 mA UVLO Rising VUR 7.5 8.0 8.5 V UVLO Falling VUF 6.5 7.0 7.5 V UVLO Hysteresis VUH 1 On-Resistance RON 68 MOSFET Output Capacitance COUT Shutdown Junction Temperature TSHDN Thermal Hysteresis THYS Overvoltage Clamp VOVC Power-On Short-Circuit Current Limit (Kelvin Sense) ISCL Operating Overload Current Limit (Kelvin Sense) VRAMP Time (0V to 12V) IOVL tVRAMP (Note 3) V 88 400 (Note 4) pF +140 +155 +175 13.5 15 16.5 V 2.75 3.44 4.25 A 40 RILIM = 15.4I (Note 4) mI NC NC RILIM = 24.9I 2.1 A RILIM = 15.4I 4.6 A RILIM = 24.9I 3.5 A CVRAMP = 270pF 7 ms CVRAMP = 470pF 12 ms CVRAMP = 1000pF 25 ms ����������������������������������������������������������������� Maxim Integrated Products 2 MAX34565 12V热插拔开关，提供TDFN封装 Electrical Characteristics (continued) (VCC = 12V, TJ = +25NC, unless otherwise noted.) PARAMETER SYMBOL EN/FAULT Fault Output Voltage CONDITIONS MIN TYP 0.82 VFAULT MAX UNITS 1.95 V Note 1: All voltages are referenced to ground. Currents entering the device are specified positive, and currents exiting the device are negative. Note 2: This supply range guarantees that the LOAD voltage is not clamped by the overvoltage limit. Note 3: Supply current specified with no load on the LOAD pin. Note 4: Guaranteed by design; not production tested. 典型工作特性 (VCC = 12V, TJ = +25°C, unless otherwise noted.) CURRENT LIMIT vs. TEMPERATURE CURRENT LIMIT (A) IOVL 4.0 3.5 ISCL 1.5 1.0 0.5 0 4 ISCL 3 2 18 21 24 27 20 40 60 80 100 120 70 60 15.6 15.4 15.2 40 80 100 120 TEMPERATURE (°C) 80 100 120 SUPPLY CURRENT vs. TEMPERATURE 2.0 1.8 1.6 1.2 1.0 0.8 0.2 0 60 60 0.4 10 14.8 40 0.6 20 10Ω LOAD 20 1.4 50 30 40 0 TEMPERATURE (°C) ICC (mA) RON (mΩ) 15.8 20 -40 -20 MAX34565 toc05 80 MAX34565 toc04 NO LOAD 0 ISCL 1.5 ON-RESISTANCE vs. TEMPERATURE OVERVOLTAGE CLAMP vs. TEMPERATURE -40 -20 2.0 TEMPERATURE (°C) 16.2 15.0 2.5 0 0 RILIM (Ω) 16.0 3.0 0.5 -40 -20 30 IOVL 1.0 0 15 RILIM = 24Ω 3.5 1 12 OVERVOLTAGE CLAMP (V) 4.0 MAX34565 toc03 IOVL MAX34565 toc06 3.0 2.5 2.0 RILIM = 15Ω 5 CURRENT LIMIT vs. TEMPERATURE 4.5 CURRENT LIMIT (A) MAX34565 toc01 5.5 5.0 4.5 CURRENT LIMIT (A) 6 MAX34565 toc02 CURRENT LIMIT vs. RILIM 6.0 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) ����������������������������������������������������������������� Maxim Integrated Products 3 MAX34565 12V热插拔开关，提供TDFN封装 典型工作特性(续) (VCC = 12V, TJ = +25°C, unless otherwise noted.) TURN-ON WAVEFORMS (VCC = 12V, EN/FAULT) TURN-ON WAVEFORMS (VCC = 12V, 10Ω RESISTIVE LOAD) MAX34565 toc07 MAX34565 toc08 RILIM = 15Ω 2V/div VCC VCC 2V/div LOAD LOAD 500mA/div EN/FAULT LOAD CURRENT 5ms/div 5ms/div TURN-ON WAVEFORMS (VCC = 12V, 3300µF CAPACITIVE LOAD) MAX34565 toc09 RILIM = 15Ω 2V/div VCC LOAD LOAD CURRENT 1A/div 5ms/div ����������������������������������������������������������������� Maxim Integrated Products 4 MAX34565 12V热插拔开关，提供TDFN封装 引脚配置 TOP VIEW LOAD LOAD LOAD LOAD LOAD 10 9 8 7 6 MAX34565 VCC/EP + 1 2 3 4 GND VRAMP EN/ ILIM FAULT 5 N.C. TDFN (3mm x 3mm) 引脚说明 引脚 名称 1 GND 功能 2 VRAMP 3 EN/FAULT 4 ILIM 电源限流值调节，该引脚与LOAD之间的电阻决定通路的限流。 5 N.C. 无连接，请勿将任何信号连接至该引脚。 接地连接。 电压缓变控制。导通期间，连接至该引脚的电容决定LOAD输出的电压缓变，电压按照公式tVRAMP = 25E6 x CVRAMP从0缓升至12V。可以将该引脚浮空，以获得最短缓升时间。 使能/故障指示。该引脚为多功能数字输入/输出引脚。在外部将该引脚拉低时，MOSFET关断；该引脚 保持开路或无外部驱动时，内部上拉基准将输入拉高，允许MOSFET导通。注：请勿在该引脚使用外部 上拉。如果器件发生热故障，该引脚将作为故障指示输出，内部拉至中间电压VFAULT。 6 7 8 LOAD 负载输出，n沟道功率MOSFET源极连接。 9 10 — VCC/EP 12V电源输入/裸焊盘。电源输入和n沟道功率MOSFET漏极连接。应连接至大面积布线或平面，EP也作 为散热器提供器件散热。 ����������������������������������������������������������������� Maxim Integrated Products 5 MAX34565 12V热插拔开关，提供TDFN封装 详细说明 器件内置68mΩ n沟道功率MOSFET，闭环控制电路确保 电流不超过可调节的限流门限。允许流过器件的最大电流 由ILIM引脚的外部电阻决定。 器件也可以控制上电输出电压缓变，连接至VRAMP引脚 的电容设置电压的爬升斜率。输出电压将无条件箝位，以 保证输入端的过压不损坏负载。器件包括带有滞回的温度 传感器，如果工作条件导致器件温度超过内部温度门限， 器件将无条件关断并闭锁，等待上电复位。发生热关断时， 器件将EN/FAULT引脚驱动至中间电压VFAULT。 欠压锁定 电压作用到VCC后，只有当电压超过欠压锁定上升门限 VUR时，才会开启MOSFET电路。VCC电压下降至VUF以下 时，将屏蔽流过MOSFET的电流。注意，为允许电流流入 LOAD引脚，VCC必须大于VUR，EN/FAULT电压必须超过 VOHT。 LOAD ENABLED EN/FAULT SIGNAL MAX34565是一款完全集成的热插拔开关，在+12V电源总 线上限制电流并控制上电时的输出电压缓变。VCC超过欠 压锁定门限VUR时，器件开始工作。此时，使能电路和EN/ FAULT引脚变为有效状态。EN/FAULT引脚电压超过VOLT 后使能器件，开始向功率MOSFET的栅极施加电压，允许 电流从VCC焊盘流至LOAD。 VOHT VFAULT 应将EN/FAULT连接至开漏引脚，以确保器件正常工作。 发生热关断时，由于器件将EN/FAULT拉至VFAULT (三态条 件)，所以该引脚不应连接外部上拉器件，典型应用电路请 参见图2。 LOAD DISABLED VOLT 图1. EN/FAULT信号电平 12V VCC LOAD MAX34565 RILIM 使能/故障指示(EN/FAULT) EN/FAULT引脚可以用作控制器输出，以指示热故障。将 EN/FAULT引脚的电压与两个内部源进行比较：电压导 通门限(VOHT)和电压关断门限(VOLT)。VCC高于VUR且EN/ FAULT电压超过VOHT时，电压开始缓慢上升并使能器件输 出。EN/FAULT的电压低于VOLT时，将禁用器件输出。如 果器件的内部温度超过TSHDN，则判断发生热故障，器件 将EN/FAULT驱动至VFAULT。关于EN/FAULT的信号电平， 请参见图1。 THERMAL SHUTDOWN/ FAULT EN/FAULT ILIM GND VRAMP ENABLE 图2. 典型应用电路 ����������������������������������������������������������������� Maxim Integrated Products 6 MAX34565 12V热插拔开关，提供TDFN封装 输出电压缓变(VRAMP) 电压缓变电路利用运放控制n沟道功率MOSFET的栅极偏 压。EN/FAULT电压低于VOLT时，利用FET保持CVRAMP放 电，强制输出电压为GND。EN/FAULT电压高于VOHT后， 内部电流源开始对连接至VRAMP引脚的外部电容CVRAMP 充电。放大器控制功率MOSFET的栅极，使(LOAD输出电 压/2)跟踪CVRAMP的上升电压。输出电压持续缓变，直到 达到输入VCC或过压箝位限制。 路检测管芯上的电压，抵消接合线电阻的影响。由于4个 LOAD引脚并联，所以导通电阻稍高。 热关断 功率MOSFET的温度达到或超过TSHDN时(大约为+155°C)， 器件进入热关断状态。超过TSHDN时，热限制电路利用使 能电路禁用器件。EN/FAULT引脚驱动至VFAULT。有两种 不同版本的器件：自动重试版本和闭锁版本。 过压限制 过压限制箝位电路监测VRAMP电压，并将其与内部电压 基准进行比较。VRAMP电压超过VOVC/2时，即使VCC处于 上升阶段，也将降低n沟道功率MOSFET的栅极电压，使 LOAD电压限制在VOVC。如果器件长时间发生过压，器件 可能会过热并进入热关断状态。这是由于功率MOSFET的 压降和负载电流产生的功耗所造成的。 ILOAD LOAD LOAD MAX34565 LOAD LOAD RLIM 电流限制 初始电压缓变(ISCL)及正常工作(IOVL)期间，持续监测负载 电流。如果电流超过ILIM上外部电阻设置的电流限值，降 低功率MOSFET的栅极电压，将输出电流降低至设置的电 流限值。器件通过将LOAD和ILIM引脚之间的电压差与内 部基准电压进行比较，限制电流。输出功率初始缓升时， 电流限值为ISCL。完成电压缓升后，电流限值为IOVL。如果 初始上电时存在短路，较低的ISCL电流限值保护电源。如 果保持高电流，器件将发热，内部温度最终将达到TSHDN。 如果功率MOSFET的温度超过关断结温TSHDN，器件类似 于保险丝，自动禁用流入负载的电流。 ILIM 图3. 直接检测电路 ILOAD LOAD LOAD TO APPLICATION LOAD MAX34565 LOAD LOAD 直接和开尔文电流检测 限流电路可以用两种方法之一进行偏置：直接检测或开尔 文检测。采用直接检测时，检测电阻连接在ILIM引脚和 LOAD引脚之间(图3)。因为全部5个LOAD引脚的接合线为 并联，所以导通电阻稍小。采用开尔文检测时，只有一个 LOAD引脚通过检测电阻连接至ILIM引脚(图4)。使用该电 TO APPLICATION LOAD RLIM ILIM 图4. 开尔文检测电路 ����������������������������������������������������������������� Maxim Integrated Products 7 MAX34565 12V热插拔开关，提供TDFN封装 闭锁版本器件 闭锁版本一旦进入热关断状态，则不再尝试打开。重新打 开器件的唯一方式是将器件电源关断后再打开。将电源重 新加至VCC焊盘，结温需要低于TSHDN，才能使能器件。 VCC 应用信息 裸焊盘(VCC) 裸焊盘为器件的电源引脚，应连接至大面积走线或平面。 裸焊盘也作为散热器，可耗散器件的热量。 0.5µF MINIMUM REQUIRED MAX34565 去耦电容 GND 正确旁路器件的电源引脚极其重要。FET关断时，去耦电 容吸收储存在电源和电路板寄生电感中的能量，从而降低 VCC过冲的幅值。可利用直接焊接在VCC和GND之间的高 质量(低ESR、低ESL)陶瓷电容实现。与旁路电容串联的任 何电阻都降低其作用，不建议使用。要求使用最小0.5µF 的陶瓷电容(图5)。然而，根据最终应用中的寄生电感，可 能有必要使用较大的电容。 限流电阻 瞬间反向雪崩击穿器件期间，与器件GND引脚串联的小电阻 (2Ω至10Ω)限值电流，从而限制注入器件的总寄生电荷(图5)。 如果使用这种方法，直接在芯片VCC和地之间跨接旁路电 容就极其重要，尽管不通过该电阻。 2Ω TO 10Ω RECOMMENDED BOARD GROUND 图5. 功率调理电路 LOAD LOAD LOAD和ILIM连接 电流通过时，LOAD引脚的接合线及连接至LOAD引脚的 走线中的小寄生电阻会造成电压偏移。由于RILIM上的压降 用于设置ISCL和IOVL限值，所以产生的偏移会使ISCL和IOVL 的值大于任意指定RILIM的规定值。为大大降低这种偏移， 建议其中一个LOAD引脚通过RILIM电阻专门连接至ILIM， 不用于传递LOAD电流ILOAD (图6)。这将保留4个LOAD引 脚传递ILOAD，应该足够。因为只有很小的电流通过这个 LOAD引脚流至ILIM，所以加至内部比较器的电压偏移可 忽略不计。这种方法是实现ILOAD准确限流值的最佳方式。 TO APPLICATION LOAD MAX34565 LOAD LOAD RLIM ILIM 图6. LOAD和ILIM连接 ����������������������������������������������������������������� Maxim Integrated Products 8 MAX34565 12V热插拔开关，提供TDFN封装 定购信息 TEMP RANGE THERMAL SHUTDOWN MAX34565ETB+ PART -40NC to +150NC Latchoff PIN-PACKAGE 10 TDFN-EP* MAX34565ETB+T -40NC to +150NC Latchoff 10 TDFN-EP* +表示无铅(Pb)/符合RoHS标准的封装。 T = 卷带包装。 *EP = 裸焊盘。 封装信息 如需最近的封装外形信息和焊盘布局(占位面积)，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。 封装类型 封装编码 10 TDFN-EP T1033+2 外形编号 21-0137 焊盘布局编号 90-0061 ����������������������������������������������������������������� Maxim Integrated Products 9 MAX34565 12V热插拔开关，提供TDFN封装 修订历史 修订号 修订日期 0 12/11 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。电气 特性表中列出的参数值(最小值和最大值)均经过设计验证，数据资料其它章节引用的参数值供设计人员参考。 Maxim Integrated Products, Inc. 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 © 2011 Maxim Integrated Products 10 Maxim是Maxim Integrated Products，Inc.的注册商标。 MAX34565 12V热插拔开关，提供TDFN封装 - 概述 Login Register 产品 方案 设计 销售联络 技术支持 公司简介 简体中文 (cn) 简体中文 (cn) 我的Maxim Maxim > 产品 > 热插拔、PoE和电源开关 > MAX34565 MAX34565 12V热插拔开关，提供TDFN封装 高度集成的自保护电子开关，确保设备安全插入、拔出12V背板 概述 技术文档 定购信息 相关产品 用户说明 (0) 所有内容 状况 状况：生产中。 数据资料 英文 概述 中文 MAX34565是一款用于12V电源的热插拔控制器。该器件为完备的集成方案，包括控制12V电源通断所需 的MOSFET。带电插入期间，器件控制电源电压的上升速度(dV/dt)并将电流限制在用户控制的范围内。该器件还 限制输出电压，以保护后续器件不受过压事件的影响。MAX34565提供闭锁版本。 下载 Rev. 0 (PDF, 1.2MB) E-Mail 下载 Rev. 0 (PDF, 1.2MB) E-Mail 现备有评估板：MAX34565EVKIT 关键特性 应用/使用 为12V电源提供完备的热插拔控制功能 集成功率MOSFET 无需大功率R SENSE 电阻 基站 InfiniBand™/ SM PCI/PCI Express® RAID/硬盘驱动器 服务器 交换机/路由器 可调节电流限制 可调整输出电压摆率 热故障报警指示 输出过压限制 内置热保护 内置电荷泵 提供闭锁版器件 关键特性: Hot Swap Controllers Part Number MAX34565 V IN (V) V IN (V) min max 9 13.2 Circuit Breaker/ Current Limit Current Limit Circuit Breaker/Current Limit Threshold (mV) Fault Condition Control Channels Adjustable Latched Off 1 Positive/Negative Rail Positive Package/Pins See Notes TDFN-EP/10 查看所有Hot Swap Controllers (53) Pricing Notes: This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor. 图表 http://china.maxim-ic.com/datasheet/index.mvp/id/7631[2012-08-28 8:46:14] Budgetary Price $0.79 @1k MAX34565 12V热插拔开关，提供TDFN封装 - 概述 Functional Diagram 没有找到你需要的产品吗？ 应用工程师帮助选型，下个工作日回复 参数搜索 应用帮助 信息索引 概述 技术文档 定购信息 相关产品 概述 关键特性 应用/使用 关键指标 图表 注释、注解 数据资料 技术文档 评估板 可靠性报告 软件/模型 价格与供货 样品 在线订购 封装信息 无铅信息 类似功能器件 类似应用器件 评估板 类似型号器件 配合该器件使用的产品 参考文献： 19- 6083 Rev. 0; 2011- 12- 21 本页最后一次更新: 2012- 08- 17 联络我们：信息反馈、提出问题 | 隐私权政策 | 法律声明 | Distributor Portal © 2012 Maxim Integrated Products版权所有 http://china.maxim-ic.com/datasheet/index.mvp/id/7631[2012-08-28 8:46:14] 19-6083; Rev 0; 12/11 MAX34565 12V Hot-Plug Switch in TDFN Package General Description The MAX34565 is a hot-plug controller for 12V power rails. It is a completely integrated solution including the required power-pass MOSFET device for 12V supplies. During hot-plug, the device controls the supply output voltage ramp (dV/dt) and limits the current at a usercontrolled level. The device also limits the output voltage to protect downstream devices from overvoltage events. The MAX34565 is offered in a latchoff version. Applications Features SCompletely Integrated Hot-Plug Functionality for 12V Power Rails SOn-Board Power MOSFET SNo High Power RSENSE Resistor Needed SAdjustable Current Limit SAdjustable Output Voltage Slew Rate SThermal Fault Indication SOutput Overvoltage Limiting SOn-Board Thermal Protection RAID/Hard Drives PCI/PCI Express® ServersInfiniBandTM/SM Switches/Routers Base Stations SOn-Board Charge Pump SLatchoff Version Ordering Information appears at end of data sheet. +12V SUPPLY Functional Diagram VCC UVLO 5V REG 68mΩ CHARGE PUMP LOAD +12V LOAD ILIM RILIM CURRENT LIMIT OVERVOLTAGE LIMIT MAX34565 GND VRAMP CVRAMP VOHT 17µA EN/FAULT 1.4V POR BLANKING THERMAL LIMIT VOLT THERMAL RESET PCI Express is a registered service mark of PCI-SIG Corp. InfiniBand is a trademark and service mark of InfiniBand Trade Association. For related parts and recommended products to use with this part, refer to: www.maxim-ic.com/MAX34565.related 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. 1 MAX34565 12V Hot-Plug Switch in TDFN Package ABSOLUTE MAXIMUM RATINGS (All voltages relative to GND.) Voltage Range on VCC Continuous..........................................................-0.3V to +18V 1ms.....................................................................-0.3V to +22V Voltage Range on ILIM, VRAMP............... -0.3V to (VCC + 0.3V), not to exceed +18V Voltage on EN/FAULT..............................................-0.3V to +6V 12V Drain Current (TA = +25NC, 0.5sq in. pad)... 3.6A (continuous) Continuous Power Dissipation (TA = +70NC) TDFN (derate at 24.4mW/NC above +70NC)............1951.2mW Operating Junction Temperature...................... -40NC to +150NC Storage Temperature Range ........................... -55NC to +150NC Lead Temperature (soldering, 10s).................................+300NC Soldering Temperature (reflow).......................................+260NC 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 (TJ = -40NC to +150NC, unless otherwise noted.) PARAMETER SYMBOL VCC Voltage VCC RILIM Value RILIM EN/FAULT Low Level (LOAD Disabled) VOLT EN/FAULT High Level (LOAD Enabled) VOHT CONDITIONS (Notes 1, 2) MIN TYP MAX UNITS 9 12 13.2 V 30 I 0.80 V 12 3.3 V ELECTRICAL CHARACTERISTICS (VCC = 12V, TJ = +25NC, unless otherwise noted.) PARAMETER SYMBOL Supply Current ICC UVLO Rising VUR UVLO Falling VUF UVLO Hysteresis VUH CONDITIONS MIN TYP MAX UNITS 1.6 2.25 mA 7.5 8.0 8.5 V 6.5 7.0 7.5 V (Note 3) 1 On-Resistance RON 68 MOSFET Output Capacitance COUT 400 Shutdown Junction Temperature TSHDN Thermal Hysteresis THYS Overvoltage Clamp VOVC Power-On Short-Circuit Current Limit (Kelvin Sense) ISCL Operating Overload Current Limit (Kelvin Sense) IOVL VRAMP Time (0V to 12V) tVRAMP (Note 4) +140 +155 V 88 pF +175 40 RILIM = 15.4I (Note 4) mI NC NC 13.5 15 16.5 V 2.75 3.44 4.25 A RILIM = 24.9I 2.1 A RILIM = 15.4I 4.6 A RILIM = 24.9I 3.5 A CVRAMP = 270pF 7 ms CVRAMP = 470pF 12 ms CVRAMP = 1000pF 25 ms 2 MAX34565 12V Hot-Plug Switch in TDFN Package ELECTRICAL CHARACTERISTICS (continued) (VCC = 12V, TJ = +25NC, unless otherwise noted.) PARAMETER SYMBOL EN/FAULT Fault Output Voltage CONDITIONS MIN VFAULT TYP 0.82 MAX UNITS 1.95 V Note 1: All voltages are referenced to ground. Currents entering the device are specified positive, and currents exiting the device are negative. Note 2: This supply range guarantees that the LOAD voltage is not clamped by the overvoltage limit. Note 3: Supply current specified with no load on the LOAD pin. Note 4: Guaranteed by design; not production tested. Typical Operating Characteristics (VCC = 12V, TJ = +25°C, unless otherwise noted.) CURRENT LIMIT vs. TEMPERATURE CURRENT LIMIT (A) IOVL 4.0 3.5 ISCL 1.5 1.0 0.5 0 4 ISCL 3 2 18 21 24 27 20 40 60 80 100 120 70 60 15.6 15.4 15.2 40 80 100 120 TEMPERATURE (°C) 80 100 120 SUPPLY CURRENT vs. TEMPERATURE 2.0 1.8 1.6 1.2 1.0 0.8 0.2 0 60 60 0.4 10 14.8 40 0.6 20 10Ω LOAD 20 1.4 50 30 40 0 TEMPERATURE (°C) ICC (mA) RON (mΩ) 15.8 20 -40 -20 MAX34565 toc05 80 MAX34565 toc04 NO LOAD 0 ISCL 1.5 ON-RESISTANCE vs. TEMPERATURE OVERVOLTAGE CLAMP vs. TEMPERATURE -40 -20 2.0 TEMPERATURE (°C) 16.2 15.0 2.5 0 0 RILIM (Ω) 16.0 3.0 0.5 -40 -20 30 IOVL 1.0 0 15 RILIM = 24Ω 3.5 1 12 OVERVOLTAGE CLAMP (V) 4.0 MAX34565 toc03 IOVL MAX34565 toc06 3.0 2.5 2.0 RILIM = 15Ω 5 CURRENT LIMIT vs. TEMPERATURE 4.5 CURRENT LIMIT (A) MAX34565 toc01 5.5 5.0 4.5 CURRENT LIMIT (A) 6 MAX34565 toc02 CURRENT LIMIT vs. RILIM 6.0 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 3 MAX34565 12V Hot-Plug Switch in TDFN Package Typical Operating Characteristics (continued) (VCC = 12V, TJ = +25°C, unless otherwise noted.) TURN-ON WAVEFORMS (VCC = 12V, EN/FAULT) TURN-ON WAVEFORMS (VCC = 12V, 10Ω RESISTIVE LOAD) MAX34565 toc07 MAX34565 toc08 RILIM = 15Ω 2V/div VCC VCC 2V/div LOAD LOAD 500mA/div EN/FAULT LOAD CURRENT 5ms/div 5ms/div TURN-ON WAVEFORMS (VCC = 12V, 3300µF CAPACITIVE LOAD) MAX34565 toc09 RILIM = 15Ω 2V/div VCC LOAD LOAD CURRENT 1A/div 5ms/div 4 MAX34565 12V Hot-Plug Switch in TDFN Package Pin Configuration TOP VIEW LOAD LOAD LOAD LOAD LOAD 10 9 8 7 6 MAX34565 VCC/EP + 1 2 3 4 GND VRAMP EN/ ILIM FAULT 5 N.C. TDFN (3mm x 3mm) Pin Description PIN NAME 1 GND FUNCTION 2 VRAMP Voltage Ramp Control. A capacitor connected to this pin determines the voltage ramp of the LOAD output during turn-on according to the equation tVRAMP = 25E6 x CVRAMP for voltage ramp from 0 to 12V. This pin can be left open circuit for a minimum ramp time. 3 EN/FAULT Enable/Fault. This pin is a multiple function digital input-output pin. When this pin is externally pulled low, the MOSFET is turned off. When this pin is left open or not externally driven, the internal pullup reference pulls the input high, and the MOSFET is allowed to turn on. Note: Do not use an external pullup on this pin. If the device experiences a thermal fault, this pin becomes an output that is pulled internally to a mid-level voltage, VFAULT. 4 ILIM Supply Current Limit Adjust. A resistor from this pin to LOAD determines the current limit for the pass connection. 5 N.C. No Connection. Do not connect any signal to this pin. Ground Connection 6 7 8 LOAD Load Output. N-channel power MOSFET source connection. 9 10 — VCC/EP 12V Supply Input/Exposed Pad. Power-supply input and n-channel power MOSFET drain connection. Should be connected to a large trace or plane. The EP also acts as a heatsink, and can dissipate heat from the device. 5 MAX34565 12V Hot-Plug Switch in TDFN Package The MAX34565 is a self-contained hot-plug switch intended to be used on +12V power buses to limit through current and to control the power-up outputvoltage ramp. The device begins to operate when VCC exceeds the undervoltage lockout level, VUR. At this level, the enable circuit and EN/FAULT pin become active. Once the device has been enabled by exceeding VOLT on the EN/FAULT pin, a gate voltage is applied to the power MOSFET, allowing current to begin flowing from the VCC pad to LOAD. The device contains an on-board 68mI n-channel power MOSFET that is actively closed-loop controlled to ensure that an adjustable current limit is not exceeded. The maximum allowable current through the device is determined by an external resistor connected to the ILIM pin. The device also contains the ability to control the powerup output-voltage ramp. A capacitor connected to the VRAMP pin sets the desired voltage ramp rate. The output voltage is unconditionally clamped to keep input overvoltage stresses from harming the load. The device has an on-board temperature sensor with hysteresis. If operating conditions cause the device to exceed an internal thermal limit, the device unconditionally shuts down and latches off while waiting for a power-on reset. In the event of thermal shutdown, the device drives the EN/FAULT pin to an intermediate voltage, VFAULT. Undervoltage Lockout When voltage is applied to VCC, the undervoltage lockout rising limit, VUR, must be exceeded before the MOSFET circuit is enabled. When the voltage on VCC drops below VUF, the current through the MOSFET is blocked. Note that to allow current to pass through to the LOAD pins, VCC must exceed VUR and the voltage on EN/FAULT must exceed VOHT. the device’s output is disabled. If the internal temperature of the device exceeds TSHDN, a thermal fault occurs and the device drives EN/FAULT to VFAULT. See Figure 1 for the EN/FAULT signal levels. An open-drain device should be connected to the EN/ FAULT pin for proper operation. Because the device pulls EN/FAULT to VFAULT (a three-state condition) in the event of thermal shutdown, this pin should not be connected to an external pullup device. See Figure 2 for a typical application circuit. LOAD ENABLED EN/FAULT SIGNAL Detailed Description THERMAL SHUTDOWN/ FAULT VOHT VFAULT LOAD DISABLED VOLT Figure 1. EN/FAULT Signal Levels 12V VCC LOAD MAX34565 RILIM EN/FAULT ILIM Enable/Fault Function (EN/FAULT) The EN/FAULT pin can be used to control the output of the device and to indicate that a thermal fault has occurred. The voltage level of the EN/FAULT pin is compared to two internal sources: voltage on limit (VOHT) and voltage off limit (VOLT). When VCC is above VUR and the voltage level on EN/FAULT exceeds VOHT, the voltage ramp circuit turns on, enabling the device’s output. When the voltage on EN/FAULT is below VOLT, GND VRAMP ENABLE Figure 2. Typical Application Circuit 6 MAX34565 12V Hot-Plug Switch in TDFN Package Output-Voltage Ramp (VRAMP) Direct and Kelvin Current Sensing The voltage ramp circuit uses an operational amplifier to control the gate bias of the n-channel power MOSFET. When the voltage on EN/FAULT is below VOLT, a FET is used to keep CVRAMP discharged, which forces the output voltage to GND. Once the voltage on EN/FAULT is above VOHT, an internal current source begins to charge the external capacitor, CVRAMP, connected to the VRAMP pin. The amplifier controls the gate of the power MOSFET so that the LOAD output voltage divided by two tracks the rising voltage level of CVRAMP. The output voltage continues to ramp until it reaches either the input VCC level or the overvoltage clamp limits. The current limit circuit can be biased in one of two ways: direct sensing or Kelvin sensing. Using direct sensing, the sense resistor is connected between the ILIM pin and the LOAD pins (Figure 3). Because the bond wires of all five LOAD pins are in parallel, the on-resistance is slightly lower. Using Kelvin sensing, only one of the LOAD pins is connected to the ILIM pin through the sense resistor (Figure 4). Using this circuit, the voltage on the die is sensed, negating any impact of the bond wire resistance. Because four LOAD pins are connected in parallel, the on-resistance is slightly higher. Overvoltage Limit The device enters a thermal shutdown state when the temperature of the power MOSFET reaches or exceeds TSHDN, approximately +155NC. When TSHDN is exceeded, the thermal-limiting circuitry disables the device using the enable circuitry. The EN/FAULT pin is driven to VFAULT. The device is offered in two different versions: an autoretry version and a latchoff version. The overvoltage-limiting clamp monitors the VRAMP voltage level compared to an internal voltage reference. When the voltage on VRAMP exceeds VOVC/2, the gate voltage of the n-channel power MOSFET is reduced, limiting the voltage on LOAD to VOVC even as VCC increases. If the device is in overvoltage for an extended period of time, the device may overheat and enter thermal shutdown. This is caused by the power created by the voltage drop across the power MOSFET and the load current. Current Limit The load current is continuously monitored during the initial voltage ramping (ISCL) and during normal operation (IOVL). If the current exceeds the current limit that is set by the external resistance at ILIM, the gate voltage of the power MOSFET is decreased, reducing the output current to the set current limit. Current is limited by the device comparing the voltage difference between the LOAD and ILIM pins to an internal reference voltage. When the output power is initially ramping up, the current limit is ISCL. Once the voltage ramping is complete, the current limit is IOVL. The lower ISCL current limit protects the source if there is a dead short on initial power-up. If the high current is maintained, the device will heat up and the internal temperature will eventually reach TSHDN. The device act as a fuse and automatically disable the current flowing to the load when the temperature of the power MOSFET has exceeded the shutdown junction temperature, TSHDN. Thermal Shutdown ILOAD LOAD LOAD TO APPLICATION LOAD MAX34565 LOAD LOAD RLIM ILIM Figure 3. Direct Sensing Circuit ILOAD LOAD LOAD TO APPLICATION LOAD MAX34565 LOAD LOAD RLIM ILIM Figure 4. Kelvin Sensing Circuit 7 MAX34565 12V Hot-Plug Switch in TDFN Package Latchoff Version Once the latchoff version has entered thermal shutdown, it does not attempt to turn back on. The only way to turn this device back on is to cycle the power to the device. When power is reapplied ton the VCC pad, the junction temperature needs to be less than TSHDN for the device to be enabled. Applications Information RILIM. To greatly reduce this offset, it is recommended that one of the LOAD pins have a dedicated connection to ILIM though RILIM, and not be used to pass the LOAD current, ILOAD (Figure 6). This would leave four LOAD pins to pass ILOAD, which should be sufficient. Because there is only a small amount of current passed from this lone LOAD pin to ILIM, there is a negligible voltage offset applied to the internal comparator. This method is the best way to attain an accurate current limit for ILOAD. Exposed Pad (VCC) The exposed pad is the voltage supply pin for the device and should be connected to a large trace or plane. The exposed pad also acts as a heatsink, and can dissipate heat from the device. Decoupling Capacitors It is of utmost importance to properly bypass the device’s supply pins. A decoupling capacitor absorbs the energy stored in the supply and board parasitic inductance when the FET is turned off, thereby reducing the magnitude of overshoot of VCC. This can be accomplished by using a high-quality (low ESR, low ESL) ceramic capacitor soldered directly between the VCC and GND connections. Any series resistance with this bypass capacitor lowers its effectiveness and is not recommended. A minimum 0.5FF ceramic capacitor is required (Figure 5). However, depending on the parasitic inductances present in the end application, a larger capacitor could be necessary. Current Limiting Resistor A small resistor (2I to 10I) in series with the GND pin of the device limits current flow during momentary reverse avalanche break down, and consequently limits total parasitic charge injected into the device (Figure 5). If this method is used, it is imperative that the bypass capacitor be directly across chip VCC and ground connections, though not through this resistor. LOAD and ILIM Connections Small parasitic resistances in the bond wires of the LOAD pins and in the traces connected to the LOAD pins can result in a voltage offset while current is flowing. Since the voltage drop across RILIM is used to set the ISCL and IOVL limits, this induced offset can increase the value of ISCL and IOVL from the specified values for any given VCC 0.5µF MINIMUM REQUIRED MAX34565 GND 2Ω TO 10Ω RECOMMENDED BOARD GROUND Figure 5. Power Conditioning Circuit LOAD TO APPLICATION LOAD LOAD MAX34565 LOAD LOAD RLIM ILIM Figure 6. LOAD and ILIM Connections 8 MAX34565 12V Hot-Plug Switch in TDFN Package Ordering Information PART TEMP RANGE THERMAL SHUTDOWN PIN-PACKAGE MAX34565ETB+ -40NC to +150NC Latchoff 10 TDFN-EP* MAX34565ETB+T -40NC to +150NC Latchoff 10 TDFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad. 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. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 10 TDFN-EP T1033+2 21-0137 90-0061 9 MAX34565 12V Hot-Plug Switch in TDFN Package Revision History REVISION NUMBER REVISION DATE 0 12/11 DESCRIPTION Initial release PAGES CHANGED — 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. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated Products, Inc. 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 © 2011 Maxim Integrated Products 10 Maxim is a registered trademark of Maxim Integrated Products, Inc.