Datasheet

LTC2977
24
2977fa
For more information www.linear.com/LTC2977
PMBus COMMAND SUMMARY
Summary Table
COMMAND NAME
CMD
CODE DESCRIPTION TYPE PAGED
DATA
FORMAT UNITS EEPROM
DEFAULT
VALUE
REF
PAGE
OT_WARN_LIMIT 0x51 Overtemperature warning limit. R/W Word N L11 °C Y 70.0
0xEA30
37
UT_WARN_LIMIT 0x52
Undertemperature warning limit. R/W Word N L11 °C Y 0
0x8000
37
UT_FAULT_LIMIT 0x53
Undertemperature fault limit. R/W Word N L11 °C Y –40.0
0xE580
37
UT_FAULT_RESPONSE
0x54 Action to be taken by the device when an
undertemperature fault is detected.
R/W Byte N Reg Y 0xB8 39
VIN_OV_FAULT_LIMIT 0x55 Input overvoltage fault limit measured at
V
IN_SNS
pin
R/W Word N L11 V Y 15.0
0xD3C0
36
VIN_OV_FAULT_
RESPONSE
0x56 Action to be taken by the device when an
input overvoltage fault is detected.
R/W Byte N Reg Y 0x80 39
VIN_OV_WARN_LIMIT 0x57 Input overvoltage warning limit measured
at V
IN_SNS
pin
R/W Word N L11 V Y 14.0
0xD380
36
VIN_UV_WARN_LIMIT 0x58 Input undervoltage warning limit
measured at V
IN_SNS
pin.
R/W Word N L11 V Y 0
0x8000
36
VIN_UV_FAULT_LIMIT 0x59 Input undervoltage fault limit measured at
V
IN_SNS
pin
R/W Word N L11 V Y 0
0x8000
36
VIN_UV_FAULT_
RESPONSE
0x5A Action to be taken by the device when an
input under
voltage fault is detected.
R/W Byte N Reg Y 0x00 39
POWER_GOOD_ON 0x5E Output voltage at or above which a power
good should be asserted.
R/W Word Y L16 V Y 0.96
0x1EB8
36
POWER_GOOD_OFF
0x5F Output voltage at or below which a power
good should be deasserted.
R/W Word Y L16 V Y 0.94
0x1E14
36
TON_DELA
Y 0x60 Time from CONTROL pin and/or
OPERATION command = ON to V
OUT_EN
pin = ON.
R/W Word Y L11 ms Y 1.0
0xBA00
37
TON_RISE 0x61 Time from when the V
OUT_EN n
pin goes
high until the LTC2977 optionally soft-
connects its DAC and begins to servo the
output voltage to the desired value.
R/W Word Y L11 ms Y 10.0
0xD280
37
TON_MAX_FAULT_LIMIT
0x62 Maximum time from V
OUT_EN
= ON
assertion that an UV condition will be
tolerated before a TON_MAX_FAULT
condition results.
R/W Word Y L11 ms Y 15.0
0xD3C0
37
TON_MAX_FAULT_
RESPONSE
0x63
Action to be taken by the device when a
TON_MAX_FAULT event is detected.
R/W Byte Y Reg Y 0xB8 40
TOFF_DELAY 0x64
Time from CONTROL pin and/or
OPERATION command = OFF to V
OUT_EN
pin = OFF.
R/W Word Y L11 ms Y 1.0
0xBA00
37
STATUS_BYTE 0x78 One byte summary of the unit’s fault
condition.
R Byte Y Reg NA 41
STATUS_WORD 0x79 Tw o byte summary of the unit’s fault
condition.
R Word Y Reg NA 41
STATUS_VOUT 0x7A Output voltage fault and warning status. R Byte Y Reg NA 42
STATUS_INPUT 0x7C Input voltage fault and warning status
measured at VIN_SNS pin.
R Byte N Reg NA 42
STATUS_TEMPERATURE 0x7D Temperature fault and warning status for
READ_TEMPERATURE_1.
R Byte N Reg NA 42