PDF《6通道智能风扇控制器》

__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. 6通道智能风扇控制器 MAX31785 19-5703;

Rev 0;

12/10 +表示无铅(Pb)/符合RoHS标准的封装. T = 卷带包装. *EP = 裸焊盘. 概述 MAX31785是一款闭环多通道风扇控制器.自动闭环风扇 控制架构将风扇控制在尽可能低的转速,从而节省系统功 率.低风扇转速的其它优势包括:有效降低可闻噪声和更 长的风扇寿命、更少的系统维护.根据用户可编程查找表 (LUT),器件根据11个温度传感器中的一个或多个传感器测 量值,自动调节6个独立风扇的转速.也可以由外部主机手 动控制风扇转速,器件自动调整风扇转速.器件具有风扇状 况诊断功能,帮助用户预防将要发生的风扇故障.器件还可 监测多达6路远端电压. 应用 网络交换机/路由器 基站 服务器 智能电网系统 工业控制 定购信息 特性 S 6路独立的风扇控制通道 支持3线和4线风扇 自动闭环风扇转速控制 基于RPM或PWM控制 可选手动控制模式 快速、慢速PWM频率选项 风扇交替启动,缓解电源压力 双转速计(支持12个风扇) 风扇故障检测 风扇运转状态监测 非易失风扇运转时间表 S 支持多达11个温度传感器 6个外部温度二极管,带有串联电阻自动抵消功能 1个内部温度传感器 4个I2 C数字温度传感器 对所有温度传感器进行故障检测 S 6路ADC测量远端电压 S PMBus?兼容命令接口 S I2 C/SMBus?兼容串行总线,带有总线超时功能 S 板载非易失故障记录和默认配置设置 S 无需外部时钟 S +3.3V供电 PMBus是SMIF, Inc.的商标. SMBus是Intel Corp.的商标. PART TEMP RANGE PIN-PACKAGE MAX31785ETL+ -40NC to +85NC

40 TQFN-EP* MAX31785ETL+T -40NC to +85NC

40 TQFN-EP* 注:该器件的某些版本可能与公布的规范存在偏差(以勘误表形式给出).通过不同的销售渠道可能获得该器件的不同版本.有关器件勘误表的详 细信息,请登录china.maxim-ic.com/errata. 6通道智能风扇控制器 MAX31785

2 目录 Absolute Maximum Ratings.6 Recommended Operating Conditions

6 DC Electrical Characteristics

6 I2C/SMBus Interface Electrical Characteristics

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 多器件连接图

13 详细说明.14 地址选择

16 SMBus/PMBus操作.16 SMBus/PMBus通信示例.16 组命令.17 组命令的写操作格式

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 主器件发送或读取过少位.18 主器件发送或读取过少字节

18 主器件发送过多字节或位

18 主器件读取过多字节或位

18 主器件在从地址字节发送不正确的读操作位.18 收到不支持的命令代码

18 收到无效数据

18 主器件读取只写命令

19 主器件写入只读命令

19 SMBus超时.19 PMBus操作.19 PMBus协议支持

19 数据格式

19 解析读取的DIRECT格式数据

20 发送DIRECT格式数据

20 故障管理与报告

21 系统看门狗定时器

21 温度传感器

21 6通道智能风扇控制器 MAX31785

3 目录(续) 风扇控制.22 双风扇应用

22 自动风扇控制.22 脉冲展宽

24 风扇起转

24 风扇上电顺序.25 风扇诊断功能.25 PMBus命令

27 PAGE (00h)27 CLEAR_FAULTS (03h)28 WRITE_PROTECT (10h)28 STORE_DEFAULT_ALL (11h)28 RESTORE_DEFAULT_ALL (12h)28 CAPABILITY (19h)28 VOUT_MODE (20h)29 VOUT_SCALE_MONITOR (2Ah)29 FAN_CONFIG_1_2 (3Ah)29 FAN_COMMAND_1 (3Bh)30 VOUT_OV_FAULT_LIMIT (40h)30 VOUT_OV_WARN_LIMIT (42h)30 VOUT_UV_WARN_LIMIT (43h)31 VOUT_UV_FAULT_LIMIT (44h)31 OT_FAULT_LIMIT (4Fh)31 OT_WARN_LIMIT (51h)31 STATUS_BYTE (78h)32 STATUS_WORD (79h)32 STATUS_VOUT (7Ah)32 STATUS_CML (7Eh)33 STATUS_MFR_SPECIFIC (80h)33 STATUS_FANS_1_2 (81h)33 READ_VOUT (8Bh)34 READ_TEMPERATURE_1 (8Dh)34 READ_FAN_SPEED_1 (90h)34 PMBUS_REVISION (98h)34 MFR_ID (99h)34 MFR_MODEL (9Ah)34 MFR_REVISION (9Bh)34 MFR_LOCATION (9Ch)34 6通道智能风扇控制器 MAX31785

4 目录(续) MFR_DATE (9Dh)34 MFR_SERIAL (9Eh)34 MFR_MODE (D1h)35 MFR_VOUT_PEAK (D4h)36 MFR_TEMPERATURE_PEAK (D6h)36 MFR_VOUT_MIN (D7h)36 MFR_FAULT_RESPONSE (D9h)36 MFR_NV_FAULT_LOG (DCh)37 MFR_TIME_COUNT (DDh)40 MFR_TEMP_SENSOR_CONFIG (F0h)40 MFR_FAN_CONFIG (F1h)41 MFR_FAN_LUT (F2h)43 温度步长:温度等级设置.43 风扇转速步长:风扇PWM占空比或风扇转速设置

44 MFR_READ_FAN_PWM (F3h)45 MFR_FAN_FAULT_LIMIT (F5h)45 MFR_FAN_WARN_LIMIT (F6h)45 MFR_FAN_RUN_TIME (F7h)46 MFR_FAN_PWM_AVG (F8h)46 MFR_FAN_PWM2RPM (F9h)46 应用信息.46 电源去耦

46 开漏引脚

46 典型工作电路

47 封装信息.47 修订历史.48 6通道智能风扇控制器 MAX31785

5 图目录 图1. 自动风扇控制

23 图2. 风扇转速控制示例

23 图3. 风扇起转

24 图4. 风扇PWM与RPM转换示例

25 图5. MFR_NV_FAULT_LOG

37 图6. 风扇查找表(LUT)格式

44 表目录 表1. PMBus命令代码

14 表2. PMBus/SMBus串口地址

16 表3. PMBus命令代码系数

20 表4. DIRECT格式数据系数.20 表5. 器件参数监测状态.21 表6. DS75LV地址引脚配置

21 表7. 风扇控制模式.22 表8. 风扇诊断

26 表9. 页命令

27 表10. WRITE_PROTECT命令字节

28 表11. CAPABILITY命令字节.28 表12. VOUT_SCALE_MONITOR.29 表13. FAN_CONFIG_1_2命令字节.29 表14. PWM风扇模式(FAN_CONFIG_1_2,第6位 = 0)30 表15. RPM风扇模式(FAN_CONFIG_1_2,第6位 = 1)30 表16. STATUS_BYTE

32 表17. STATUS_WORD

32 表18. STATUS_VOUT

32 表19. STATUS_CML

33 表20. STATUS_MFR_SPECIFIC

33 表21. STATUS_FANS_1_2

33 表22. MFR_MODE

35 表23. MFR_FAULT_RESPONSE

36 表24. MFR_NV_FAULT_LOG.38 表25. MFR_TEMP_SENSOR_CONFIG

40 表26. MFR_FAN_CONFIG

41 表27. MFR_FAN_LUT

43 表28. 有效温度范围.43 表29. 监测风扇故障和报警参数

45 表30. MFR_FAN_PWM2RPM

46 6通道智能风扇控制器 MAX31785

6 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. 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 Operating Temperature Range.40NC to +85NC Storage Temperature Range. 55NC to +125NC Lead Temperature (soldering, 10s)260NC Soldering Temperature (reflow)260NC Recommended Operating Conditions (TA = -40NC to +85NC.) Absolute Maximum Ratings 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.) *Subject to not exceeding +5.5V. PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS VDD Operating Voltage Range VDD (Note 1) 2.7 5.5 V Input Logic

1 VIH 0.7 x VDD VDD + 0.3 V Input Logic

0 VIL -0.3 0.3 x VDD V 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) -0.5 +0.8 V PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Current ICPU (Note 2)

3 mA IPROGRAM

8 Brownout Voltage VBO Monitors VDD (Note 1) 2.40 2.46 2.55 V Brownout Hysteresis VBOH Monitors VDD (Note 1)

30 mV Internal System Clock fMOSC 4.0 MHz System Clock Error (Note 3) fERR:MOSC +25NC P TA P +85NC -3 +2 % -40NC P TA P +25NC -6.5 +1.6 Output Logic-Low VOL1 IOL = 4mA (Note 1) 0.4 V Output Logic-High VOH1 IOH = -2mA (Note 1) VDD - 0.5 V PWM Pullup Current IPU VPIN = VSS, VDD = 3.3V

38 55

107 FA ADC Internal Reference 1.225 V ADC Voltage Measurement Error VERR -1 +1 % 6通道智能风扇控制器 MAX31785

7 DC Electrical characteristics (continued) (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 ADC Internal Reference Temperature Drift -0.5 +0.5 % ADC Internal Reference Initial Accuracy (+25NC) -1 +1 mV ADC Full-Scale Input Voltage VFS 1.213 1.225 1.237 V ADC Measurement Resolution VLSB

300 FV ADC Bit Resolution

12 Bits RS+ Input Resistance RIN

15 MI ADC Integral Nonlinearity INL Q4 LSB ADC Differential Nonlinearity DNL Q1 LSB ADC Offset VOFFSET Q2 LSB Internal Temperature Measurement Error TA = -40NC to +85NC -3 +3 NC Remote Temperature Measurement Error (MAX31785 Error Only) TA = 0NC to +60NC, TDIODE = +60NC to +120NC -1.5 +1.5 NC TA = 0NC to +60NC, TDIODE = -45NC to +120NC -1.75 +1.75 TA = -40NC to +85NC, TDIODE = +60NC to +120NC -2.75 +2.75 TA = -40NC to +85NC, TDIODE = -45NC to +120NC -3.0 +3.0 Store Default All Time

45 ms Nonvolatile Log Write Time

12 ms Nonvolatile Log Delete Time

200 ms Flash Endurance NFLASH TA = +50NC 20,000 Write Cycles Data Retention TA = +50NC

100 Years Voltage Sample Rate

10 ms RPM Sample Rate

1000 ms Temperature Sample Rate

1000 ms Device Startup Time Measured from POR until monitoring begins

12 ms Fan PWM Frequency

30 25,000 Hz Fan PWM Resolution

7 Bits 6通道智能风扇控制器 MAX31785

8 I2C/SMBus Interface 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.) 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 PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SCL Clock Frequency fSCL

10 100 kHz 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 Data Hold Time tHD:DAT Receive

0 ns Transmit

300 Data Setup Time tSU:DAT

100 ns START Setup Time tSU:STA 4.7 Fs SDA and SCL Rise Time tR

300 ns SDA and SCL Fall Time tF

300 ns STOP Setup Time tSU:STO 4.0 Fs Clock Low Timeout tTO

25 35 ms SCL NOTE: TIMING IS REFERENCED TO VIL(MAX) AND VIH(MIN). SDA STOP START REPEATED START tBUF tHD:STA tHD:DAT tSU:DAT tSU:STO tHD:STA tSP tSU:STA tHIGH tR tF tLOW 6通道智能风扇控制器 MAX31785

9 典型工作特性 (TA = +25°C, unless otherwise noted.) FAN POWER-ON SEQUENCING MAX31785 toc05 100ms/div 0V 0V 0V 0V 5V/div PWM2 PWM1 PWM0 CONTROL IDD vs. TIME DURING A NONVOLATILE LOG WRITE (TA = +25°C, VDD = 3.3V) MAX31785 toc04 2ms/div 0mA 1mA/div WEAK PULLUP VOLTAGE vs. TIME DURING POWER-UP MAX31785 toc03 2ms/div 0V VDD PWMO 0V NO LOAD CONNECTED TO PWM 2V/div ........