LTC2972 2-Channel PMBus Power System Manager Featuring Programmable Power Good Outputs FEATURES DESCRIPTION n Sequence, Trim, Margin and Supervise Two The LTC 2972 is a 2-channel Power System Manager PowerSupplies used to sequence, trim (servo), margin, supervise, man- n Manage Faults, Monitor Telemetry age faults, provide telemetry and create fault logs. PMBus n PMBus Compliant Command Set commands support power supply sequencing, precision n Supported by LTpowerPlay GUI point-of-load voltage adjustment and margining. DACs n Margin or Trim Supplies to Within 0.25% of Target use a proprietary soft-connect algorithm to minimize sup- n Monitor Input Current (1%) and Accumulate Energy ply disturbances. Supervisory functions include over and n Fast OV/UV Supervisors per Channel under voltage and temperature threshold limits for two n Coordinate Sequencing and Fault Management power supply output channels as well as over and under Across Multiple ADI PSM Devices voltage threshold limits for a single power supply input n Automatic Fault Logging to Internal EEPROM channel. Programmable fault responses can disable the n Operate Autonomously Without Additional Software power supplies with optional retry after a fault is detected. n Configurable Power Good Output Pins Faults that disable a power supply can automatically trigger n Accurate Monitoring of Output Voltage, Output black box EEPROM storage of fault status and associated Current, Temperature, and Input Voltage and Current telemetry. An internal 16-bit ADC monitors two output volt- 2 n 1.8V to 3.3V I C/SMBus Serial Interface ages, two output currents, two external temperatures, input n Connect Directly to Regulator IMON Pins voltage and current, and die temperature. Input power, n Can Be Powered from 3.3V, or 4.5V to 15V energy, and output power are also calculated. A program- n Available in 44-Pin 6mm 7mm QFN Package mable watchdog timer monitors microprocessor activity for a stalled condition and resets the microprocessor if neces- sary. A single wire bus synchronizes power supplies across APPLICATIONS multiple ADI Power System Management (PSM) devices. n Computers and Network Servers Configuration EEPROM with ECC supports autonomous n Industrial Test and Measurement operation without additional software. n High Reliability Systems All registered trademarks and trademarks are the property of their respective owners. Protected n by U.S. Patents including 7382303, 7420359, 8648623 and8920026. Video and Medical Imaging TYPICAL APPLICATION Closed-Loop Servo Error vs Temperature IBC 4.5V V 15V IBUS 0.25 DC IN OUT IN 80 PARTS SOLDERED DOWN 0.20 V = 1.0V IN ALERTB PMBus 0.15 CONTROL SCL INTERFACE SDA FAULT 0.10 V * DD33 PWRGD V DDIO 0.05 I I SENSEP0 SENSEP1 V V IN IN R SNS I I R 0.00 SENSEM0 SENSEM1 SNS V V OUT OUT V V SENSEP1 SENSEP0 LTC2972 0.05 DC/DC DC/DC R20 R20 CONVERTER LOAD LOAD CONVERTER 0.10 V V V RUN RUN V SENSEM0 SENSEM1 FB FB 0.15 R10 R10 R30 R30 V V DAC0 DAC1 0.20 V OUT EN0 VOUT EN1 0.25 PG0 PG1 50 25 0 25 50 75 100 *LTC2972 MAY ALSO BE T T SENSE0 SENSE1 NOTE: SOME DETAILS POWERED DIRECTLY FROM 2972 TA01a TEMPERATURE (C) OMITTED FOR CLARITY AN EXTERNAL 3.3V SUPPLY 2972 TA01b Rev. C 1 Document Feedback For more information www.analog.com V IN SNS V * PWR I IN SNSP I IN SNSM ERROR (% OF READING)LTC2972 TABLE OF CONTENTS Features ............................................................................1 VIN ON, VIN OFF, VIN OV FAULT LIMIT, VIN OV WARN Applications .......................................................................1 LIMIT, VIN UV WARN LIMIT and Typical Application ...............................................................1 VIN UV FAULT LIMIT ................................................................. 49 Description.........................................................................1 INPUT Current and ENERGY .............................................................. 49 Absolute Maximum Ratings .....................................................4 Energy Measurement and Reporting ........................................... 49 Order Information .................................................................4 MFR EIN ..................................................................................... 49 Pin Configuration .................................................................4 MFR EIN CONFIG ....................................................................... 50 Electrical Characteristics ........................................................5 MFR IIN CAL GAIN ....................................................................51 PMBus Timing Diagram ........................................................ 11 MFR IIN CAL GAIN TC ..............................................................51 Typical Performance Characteristics ........................................ 12 MFR CLEAR ENERGY .................................................................51 Pin Functions .................................................................... 16 Output Voltage Commands and Limits.............................................. 52 Block Diagram ................................................................... 18 VOUT MODE ................................................................................ 52 Operation......................................................................... 19 VOUT COMMAND, VOUT MAX, VOUT MARGIN HIGH, VOUT LTC2972 Operation Overview .............................................................19 MARGIN LOW, VOUT OV FAULT LIMIT, EEPROM ....................................................................................... 20 VOUT OV WARN LIMIT, VOUT UV WARN LIMIT, VOUT UV AUXFAULTB ....................................................................................... 20 FAULT LIMIT, POWER GOOD ON and RESETB .............................................................................................. 20 POWER GOOD OFF .................................................................... 53 V MFR VOUT DISCHARGE THRESHOLD ...................................... 53 DDIO .....................................................................................................................20 PMBus Serial Digital Interface .......................................................... 21 MFR DAC STARTUP ................................................................... 53 PMBus .......................................................................................... 21 MFR DAC ..................................................................................... 53 Device Address ............................................................................ 21 Output CURRENT Commands and Limits ......................................... 54 Processing Commands ................................................................ 21 IOUT CAL GAIN and IOUT CAL OFFSET .................................. 54 Addressing and Write Protect ........................................................... 31 IOUT OC WARN LIMIT .............................................................. 54 PAGE ............................................................................................ 31 MFR IOUT CAL GAIN TC .......................................................... 54 WRITE PROTECT ........................................................................ 32 External Temperature Commands and Limits ................................... 55 WRITE PROTECT Pin ................................................................... 32 OT FAULT LIMIT, OT WARN LIMIT, UT WARN LIMIT and MFR PAGE FF MASK ................................................................. 33 UT FAULT LIMIT ......................................................................... 56 MFR I2C BASE ADDRESS ........................................................ 33 MFR TEMP 1 GAIN and MFR TEMP 1 OFFSET ....................... 56 MFR COMMAND PLUS .............................................................. 33 MFR T SELF HEAT, MFR IOUT CAL GAIN TAU INV and MFR MFR DATA PLUS0 and MFR DATA PLUS1 .............................. 33 IOUT CAL GAIN THETA ............................................................. 56 MFR STATUS PLUS0, and MFR STATUS PLUS1 .................... 33 Sequencing Timing Limits and Clock Sharing................................... 58 Reading Fault Log Using Command Plus and MFR DATA PLUS0 . 34 TON DELAY, TON RISE, TON MAX FAULT LIMIT and TOFF Reading Energy Using MFR COMMAND PLUS and MFR DATA DELAY .......................................................................................... 58 PLUS0 .......................................................................................... 35 MFR RESTART DELAY ............................................................... 59 Peek Operation Using MFR DATA PLUS0 .................................. 35 Clock Sharing ............................................................................... 59 Enabling and Disabling Poke Operations ..................................... 35 Watchdog Timer and Power Good ..................................................... 59 Poke Operation Using Mfr data plus0 ....................................... 36 MFR PG CONFIG ........................................................................ 60 Command Plus Operations Using MFR DATA PLUS1 ............... 36 MFR PG GPO ............................................................................. 62 On/Off Control, Margining and Configuration ................................... 36 MFR PWRGD EN ........................................................................ 62 OPERATION .................................................................................. 37 MFR POWERGOOD ASSERTION DELAY .................................. 62 ON OFF CONFIG ......................................................................... 38 Watchdog Operation .................................................................... 63 MFR CONFIG LTC2972 .............................................................. 38 MFR WATCHDOG T FIRST and MFR WATCHDOG T ............... 63 Cascade Sequence ON with Time-Based Sequence OFF ............. 40 Fault Responses ................................................................................ 63 MFR CONFIG2 LTC2972 .............................................................41 Clearing Latched Faults ............................................................... 64 MFR CONFIG3 LTC2972 .............................................................41 VOUT OV FAULT RESPONSE and VOUT UV FAULT RESPONSE Tracking Supplies On and Off ...................................................... 42 64 Tracking Implementation ............................................................. 42 OT FAULT RESPONSE, UT FAULT RESPONSE, VIN OV FAULT MFR CONFIG ALL LTC2972 ..................................................... 44 RESPONSE and VIN UV FAULT RESPONSE.............................. 65 Programming User EEPROM Space .................................................. 46 TON MAX FAULT RESPONSE ................................................... 65 STORE USER ALL and RESTORE USER ALL .......................... 46 MFR RETRY DELAY ................................................................... 66 MFR EE UNLOCK ....................................................................... 47 MR RETRY COUNT .................................................................... 66 MFR EE ERASE .......................................................................... 47 Shared External Faults ....................................................................... 67 MFR EE DATA ............................................................................. 47 MFR FAULTB0 PROPAGATE and MFR FAULTB1 PROPAGATE 67 Response When Part Is Busy....................................................... 48 MFR FAULTB0 RESPONSE and MFR FAULTB1 RESPONSE ... 67 MFR EE Erase and Write Programming Time ............................. 48 Fault Warning and Status .................................................................. 68 Input Voltage Commands and Limits ................................................ 48 CLEAR FAULTS ........................................................................... 68 Rev. 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