LTC2978A 8-Channel PMBus Power NOT RECOMMENDED FOR NEW DESIGNS Please See LTC2977 for Replacement System Manager Featuring Accurate Output Voltage Measurement FEATURES DESCRIPTION n Sequence, Trim, Margin and Supervise Eight Power Supplies The LTC 2978A is an 8-channel Power System Manager n Manage Faults, Monitor Telemetry and Create Fault Logs used to sequence, trim (servo), margin, supervise, man- n PMBus Compliant Command Set age faults, provide telemetry and create fault logs. PMBus n Supported by LTpowerPlay GUI commands support power supply sequencing, precision n Margin or Trim Supplies to 0.25% Accuracy point-of-load voltage adjustment and margining. DACs use n Fast OV/UV Supervisors per Channel a proprietary soft-connect algorithm to minimize supply n Coordinate Sequencing and Fault Management disturbances. Supervisory functions include overvoltage Across Multiple Chips and undervoltage threshold limits for eight power supply n Automatic Fault Logging to Internal EEPROM output channels and one power supply input channel, as n Operate Autonomously without Additional Software well as over and under temperature limits. Programmable n Internal Temperature and Input Voltage Supervisors fault responses can disable the power supplies with optional n Accurate Monitoring of Eight Output Voltages, Input retry after a fault is detected. Faults that disable a power Voltage and Internal Die Temperature supply can automatically trigger black box EEPROM storage 2 n I C/SMBus Serial Interface of fault status and associated telemetry. An internal 16-bit n Can Be Powered from 3.3V, or 4.5V to 15V ADC monitors eight output voltages, one input voltage, n Programmable Watchdog Timer and die temperature. In addition, odd numbered chan- n 100% Compatible with the LTC2978 nels can be configured to measure the voltage across a n Available in 64-pin 9mm 9mm QFN Package current sense resistor. A programmable watchdog timer monitors microprocessor activity for a stalled condition and resets the microprocessor if necessary. A single wire bus APPLICATIONS synchronizes power supplies across multiple ADI power n Computers and Network Servers system management devices. Configuration EEPROM sup- n Industrial Test and Measurement ports autonomous operation without additional software. n High Reliability Systems All registered trademarks and trademarks are the property of their respective owners. Protected n Medical Imaging by U.S. Patents including 7382303, 7420359 and 7940091. n Video TYPICAL APPLICATION Typical ADC Total Unadjusted 8-Channel PMBus Power System Manager Error vs Temperature 0.035 4.5V < V < 15V** V IBUS IN ADC V = 1.8V IN 0.030 V V V PWR IN SNS OUT 3.3V** V V DIGITALLY DD33 DACP0 0.025 MANAGED V R30 TO INTERMEDIATE SENSEP0 V POWER IN EN BUS CONVERTER ENABLE R20 SUPPLY 0.020 LTC2978A* SDA V LOAD FB SCL V 0.015 PMBus DACM0 R10 INTERFACE ALERTB V SGND SENSEM0 0.010 CONTROL0 V RUN/SS OUT EN0 GND 0.005 WRITE-PROTECT WP PWRGD TO P RESETB INPUT WDI/RESETB WATCHDOG 0 100 TIMER INTERRUPT 50 35 20 5 10 25 40 55 70 85 TO/FROM OTHER FAULTB00 ASEL0 TEMPERATURE (C) LTC2978s SHARE CLK ASEL1 *SOME DETAILS OMITTED FOR CLARITY 2978a TA01b ONLY ONE OF EIGHT CHANNELS SHOWN GND 2978a TA01a **LTC2978A MAY BE POWERED FROM EITHER AN EXTERNAL 3.3V SUPPLY OR THE INTERMEDIATE BUS 2978afb 1 For more information www.linear.com/LTC2978A ERROR (%)LTC2978A TABLE OF CONTENTS Features ..................................................... 1 Input Voltage Related Commands ...........................34 Applications ................................................ 1 VIN ON, VIN OFF, VIN OV FAULT LIMIT, VIN Typical Application ........................................ 1 OV WARN LIMIT, VIN UV WARN LIMIT and Description.................................................. 1 VIN UV FAULT LIMIT .......................................34 Absolute Maximum Ratings .............................. 4 Temperature Related Commands ............................35 Order Information .......................................... 4 OT FAULT LIMIT, OT WARN LIMIT, UT WARN Pin Configuration .......................................... 4 LIMIT and UT FAULT LIMIT ...............................35 Electrical Characteristics ................................. 5 Timer Limits ...........................................................35 PMBus Timing Diagram ................................... 9 TON DELAY, TON RISE, TON MAX FAULT Typical Performance Characteristics .................. 10 LIMIT and TOFF DELAY......................................35 Pin Functions .............................................. 15 Fault Response for Voltages Measured by the High Block Diagram ............................................. 17 Speed Supervisor ...................................................36 Operation................................................... 18 VOUT OV FAULT RESPONSE and VOUT UV Operation Overview ................................................ 18 FAULT RESPONSE .............................................36 EEPROM ............................................................. 18 Fault Response for Values Measured by the ADC ...37 Reset ...................................................................... 19 OT FAULT RESPONSE, UT FAULT RESPONSE, Write-Protect Pin .................................................... 19 VIN OV FAULT RESPONSE and VIN UV FAULT Other Operations .................................................... 19 RESPONSE .........................................................37 Clock Sharing ..................................................... 19 Timed Fault Response ............................................37 PMBus Serial Digital Interface ................................20 TON MAX FAULT RESPONSE ..........................37 PMBus ................................................................20 Status Commands ..................................................38 Device Address ...................................................23 STATUS BYTE ....................................................38 Processing Commands ....................................... 24 STATUS WORD ..................................................39 Summary Table ...................................................25 STATUS VOUT ...................................................39 PMBus Command Summary ............................ 25 STATUS INPUT ..................................................40 Data Formats ......................................................29 STATUS TEMPERATURE ....................................40 PMBus Command Description .......................... 30 STATUS CML ..................................................... 41 Operation, Mode and EEPROM Commands ............30 STATUS MFR SPECIFIC .................................... 41 PAGE ..................................................................30 ADC Monitoring Commands ...................................42 OPERATION ........................................................31 READ VIN ..........................................................42 ON OFF CONFIG ................................................32 READ VOUT .......................................................42 CLEAR FAULTS..................................................32 READ TEMPERATURE 1 ..................................42 WRITE PROTECT ...............................................33 PMBUS REVISION .............................................42 STORE USER ALL and RESTORE USER ALL .33 Manufacturer Specific Commands ..........................43 CAPABILITY ........................................................ 33 MFR CONFIG LTC2978 .....................................43 VOUT MODE ......................................................34 MFR CONFIG ALL LTC2978 ............................44 Output Voltage Related Commands ........................34 MFR FAULTBz0 PROPAGATE, MFR FAULTBz1 VOUT COMMAND, VOUT MAX, VOUT MARGIN PROPAGATE .......................................................45 HIGH, VOUT MARGIN LOW, VOUT OV FAULT MFR PWRGD EN ..............................................46 LIMIT, VOUT OV WARN LIMIT, VOUT UV MFR FAULTB00 RESPONSE, MFR FAULTB01 WARN LIMIT, VOUT UV FAULT LIMIT, POWER RESPONSE, MFR FAULTB10 RESPONSE and GOOD ON and POWER GOOD OFF ..................34 MFR FAULTB11 RESPONSE .............................. 47 2978afb 2 For more information www.linear.com/LTC2978A