Datasheet

LTC2978A
2
2978afa
For more information www.linear.com/LTC2978A
TABLE OF CONTENTS
Features ..................................................... 1
Applications ................................................ 1
Typical Application ........................................ 1
Description.................................................. 1
Absolute Maximum Ratings .............................. 4
Order Information .......................................... 4
Pin Configuration .......................................... 4
Electrical Characteristics ................................. 5
PMBus Timing Diagram ................................... 9
Typical Performance Characteristics .................. 10
Pin Functions .............................................. 15
Block Diagram ............................................. 17
Operation................................................... 18
Operation Overview ................................................ 18
EEPROM ............................................................. 18
Reset ...................................................................... 19
Write-Protect Pin .................................................... 19
Other Operations .................................................... 19
Clock Sharing ..................................................... 19
PMBus Serial Digital Interface ................................ 20
PMBus ................................................................20
Device Address ...................................................23
Processing Commands ....................................... 24
Summary Table ...................................................25
PMBus
Command Summary ............................ 25
Data Formats ...................................................... 29
PMBus
Command Description .......................... 30
Operation, Mode and EEPROM Commands ............30
PAGE ..................................................................30
OPERATION ........................................................31
ON_OFF_CONFIG ................................................ 32
CLEAR_FAULTS..................................................32
WRITE_PROTECT ...............................................33
STORE_USER_ALL and RESTORE_USER_ALL .33
CAPABILITY ........................................................33
VOUT_MODE ......................................................34
Output Voltage Related Commands ........................34
VOUT_COMMAND, VOUT_MAX, VOUT_MARGIN_
HIGH, VOUT_MARGIN_LOW, VOUT_OV_FAULT_
LIMIT, VOUT_OV_WARN_LIMIT, VOUT_UV_
WARN_LIMIT, VOUT_UV_FAULT_LIMIT, POWER_
GOOD_ON and POWER_GOOD_OFF ..................34
Input Voltage Related Commands ...........................34
VIN_ON, VIN_OFF, VIN_OV_FAULT_LIMIT, VIN_
OV_WARN_LIMIT, VIN_UV_WARN_LIMIT and
VIN_UV_FAULT_LIMIT .......................................34
Temperature Related Commands ............................35
OT_FAULT_LIMIT, OT_WARN_LIMIT, UT_WARN_
LIMIT and UT_FAULT_LIMIT ...............................35
Timer Limits ...........................................................35
TON_DELAY, TON_RISE, TON_MAX_FAULT_
LIMIT and TOFF_DELAY......................................35
Fault Response for Voltages Measured by the High
Speed Supervisor ...................................................36
VOUT_OV_FAULT_RESPONSE and VOUT_UV_
FAULT_RESPONSE .............................................36
Fault Response for Values Measured by the ADC ...37
OT_FAULT_RESPONSE, UT_FAULT_RESPONSE,
VIN_OV_FAULT_RESPONSE and VIN_UV_FAULT_
RESPONSE .........................................................37
Timed Fault Response ............................................37
TON_MAX_FAULT_RESPONSE ..........................37
Status Commands ..................................................38
STATUS_BYTE ....................................................38
STATUS_WORD ..................................................39
STATUS_VOUT ...................................................39
STATUS_INPUT ..................................................40
STATUS_TEMPERATURE ....................................40
STATUS_CML ..................................................... 41
STATUS_MFR_SPECIFIC .................................... 41
ADC Monitoring Commands ...................................42
READ_VIN ..........................................................42
READ_VOUT ....................................................... 42
READ_TEMPERATURE_1 ..................................42
PMBUS_REVISION .............................................42
Manufacturer Specific Commands ..........................43
MFR_CONFIG_LTC2978 .....................................43
MFR_CONFIG_ALL_LTC2978 ............................44
MFR_FAULTBz0_PROPAGATE, MFR_FAULTBz1_
PROPAGATE .......................................................45
MFR_PWRGD_EN ..............................................46
MFR_FAULTB00_RESPONSE, MFR_FAULTB01_
RESPONSE, MFR_FAULTB10_RESPONSE and
MFR_FAULTB11_RESPONSE .............................. 47