Datasheet

LTC2977
2
2977fa
For more information www.linear.com/LTC2977
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 .............................................. 13
Block Diagram ............................................. 15
Operation................................................... 16
Operation Overview ................................................ 16
EEPROM ............................................................. 17
Reset ...................................................................... 17
Write-Protect Pin .................................................... 17
Other Operations .................................................... 17
Clock Sharing ..................................................... 17
PMBus Serial Digital Interface ................................ 18
PMBus ................................................................ 18
Device Address ...................................................21
Processing Commands .......................................22
PMBus Command Summary ............................ 23
Summary Table ...................................................23
Data Formats ...................................................... 27
PMBus Command Description .......................... 28
Addressing and Write Protect ................................. 28
PAGE ..................................................................28
WRITE_PROTECT ...............................................28
MFR_PAGE_FF_MASK .......................................29
MFR_I2C_BASE_ADDRESS ...............................29
MFR_COMMAND_PLUS, MFR_DATA_PLUS0,
MFR_DATA_PLUS1, MFR_STATUS_PLUS0, and
MFR_STATUS_PLUS1 ........................................30
Reading Fault Log Using Command Plus and
Mfr_data_plus0 ..................................................31
Peek Operation using Mfr_data_plus0 ...............32
Enabling and Disabling Poke Operations ............32
Poke Operation Using Mfr_data_plus0 ...............32
Command Plus Operations Using Mfr_data_plus1 . 32
Operation, Mode and EEPROM Commands ............33
OPERATION ........................................................ 33
ON_OFF_CONFIG ................................................ 34
CLEAR_FAULTS..................................................34
STORE_USER_ALL and RESTORE_USER_ALL .35
CAPABILITY ........................................................35
VOUT_MODE ......................................................35
Output Voltage Related Commands ........................36
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 ..................36
Input Voltage Related Commands ...........................36
VIN_ON, VIN_OFF, VIN_OV_FAULT_LIMIT, VIN_
OV_WARN_LIMIT, VIN_UV_WARN_LIMIT and
VIN_UV_FAULT_LIMIT .......................................36
Temperature Related Commands ............................37
OT_FAULT_LIMIT, OT_WARN_LIMIT, UT_WARN_
LIMIT and UT_FAULT_LIMIT ...............................37
Timer Limits ...........................................................37
TON_DELAY, TON_RISE, TON_MAX_FAULT_
LIMIT and TOFF_DELAY......................................37
Fault Response for Voltages Measured by the High
Speed Supervisor ...................................................38
VOUT_OV_FAULT_RESPONSE and VOUT_UV_
FAULT_RESPONSE .............................................38
Fault Response for Values Measured by the ADC ...39
OT_FAULT_RESPONSE, UT_FAULT_RESPONSE,
VIN_OV_FAULT_RESPONSE and VIN_UV_FAULT_
RESPONSE .........................................................39
Timed Fault Response ............................................40
TON_MAX_FAULT_RESPONSE ..........................40
Status Commands .................................................. 41
STATUS_BYTE ....................................................41
STATUS_WORD .................................................. 41
STATUS_VOUT ...................................................42
STATUS_INPUT .................................................. 42
STATUS_TEMPERATURE ....................................42
STATUS_CML ..................................................... 43
STATUS_MFR_SPECIFIC .................................... 43
ADC Monitoring Commands ...................................44
READ_VIN ..........................................................44
READ_VOUT ....................................................... 44
READ_TEMPERATURE_1 ...................................44
PMBUS_REVISION ............................................. 44
Manufacturer Specific Commands ..........................45
MFR_CONFIG_LTC2977 ..................................... 45
Tracking Supplies On and Off .............................46
Tracking Implementation ....................................48
MFR_CONFIG_ALL_LTC2977 ............................49
MFR_FAULTBz0_PROPAGATE, MFR_FAULTBz1_
PROPAGATE .......................................................50
MFR_PWRGD_EN .............................................. 51