MAX34441 19-5488 Rev 1 1/12 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller General Description Features The MAX34441 is a complex system monitor that can man- S 5 Channels of Power-Supply Management age up to five power supplies and a fan. The power-supply Voltage Measurement/Monitoring manager monitors the power-supply output voltage and Differential 12-Bit 1% Accurate ADC constantly checks for user-programmable overvoltage and Min/Max Threshold Excursion Detection undervoltage thresholds. It can also margin the power- Supports Current Monitoring with External supply output voltage up or down to a user-programma- Current-Sense Amplifier ble level. The margining is performed in a closed-loop Automatic Closed-Loop Margining arrangement whereby the device automatically adjusts Programmable Up and Down Sequencing a pulse-width-modulated (PWM) output and then mea- Power-Good Output sures the resultant output voltage. The power-supply S 1 Channel of Fan Control manager can also sequence the supplies in any order Supports 3-Wire and 4-Wire Fans at both power-up and power-down. With the addition of Automatic Closed-Loop Fan-Speed Control an external current-sense amplifier, the device can also Support for Dual Tachometer Fans monitor currents. Fan-Fault Detection The device also contains closed-loop fan-speed control. S Supports Up to Six Temperature Sensors Based on user-programmable settings for fan-control External Thermal Diode Interface with PWM duty cycles or RPM speeds at particular tempera- Automatic Series Resistance Cancellation ture breakpoints, the device automatically adjusts the fan One Internal Temperature Sensor speed in a manner to reduce audible noise and power 2 Support for Up to Four Additional I C Digital consumption. Temp Sensor ICs Fault Detection on All Temp Sensors Applications S PMBus-Compliant Command Interface Network Switches/Routers 2 S I C/SMBus-Compatible Serial Bus with Bus Base Stations Timeout Function Servers S On-Board Nonvolatile Fault Logging and Default Smart Grid Network Systems Configuration Setting Industrial Controls S No External Clocking Required S +3.3V Supply Voltage Ordering Information PART TEMP RANGE PIN-PACKAGE MAX34441ETL+ -40NC to +85NC 40 TQFN-EP* MAX34441ETL+T -40NC to +85NC 40 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad. PMBus is a trademark of SMIF, Inc. Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, go to: www.maxim-ic.com/errata. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller TABLE OF CONTENTS Absolute Maximum Ratings 6 Recommended Operating Conditions 6 DC Electrical Characteristics . 6 2 Electrical Specifications: I C/SMBus Interface . 8 2 I C/SMBus Timing . 8 Typical Operating Characteristics . 9 Pin Configuration . 10 Pin Description . 10 Block Diagram . 12 Multiple Device Connection Diagram 13 Detailed Description . 14 Address Select . 16 SMBus/PMBus Operation . 16 SMBus/PMBus Communication Examples . 16 Group Command . 17 Group Command Write Format 17 Addressing 17 ALERT and Alert Response Address (ARA) . 17 Alert Response Address (ARA) Byte Format 18 Host Sends or Reads Too Few Bits . 18 Host Sends or Reads Too Few Bytes 18 Host Sends Too Many Bytes or Bits . 18 Host Reads Too Many Bytes or Bits . 18 Host Sends Improperly Set Read Bit in the Slave Address Byte . 18 Unsupported Command Code Received . 18 Invalid Data Received 18 Host Reads from a Write-Only Command 19 Host Writes to a Read-Only Command . 19 SMBus Timeout . 19 PMBus Operation . 19 PMBus Protocol Support 19 Data Format 19 Interpreting Received DIRECT Format Values .20 Sending a DIRECT Format Value .20 Fault Management and Reporting 21 System Watchdog Timer 22 Temperature Sensor Operation .22 2 MAX34441