Datasheet

LTC2977
23
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
PAGE 0x00 Channel or page currently selected for any
command that supports paging.
R/W Byte N Reg 0x00 28
OPERATION 0x01 Operating mode control. On/Off, Margin
High and Margin Low.
R/W Byte Y Reg Y 0x00 33
ON_OFF_CONFIG 0x02 CONTROL pin & PMBus bus on/off
command setting.
R/W Byte Y Reg Y 0x1E 34
CLEAR_FAULTS 0x03 Clear any fault bits that have been set. Send Byte Y NA 34
WRITE_PROTECT 0x10 Level of protection provided by the device
against accidental changes.
R/W Byte N Reg Y 0x00 28
STORE_USER_ALL 0x15 Store entire operating memory to
EEPROM.
Send Byte N NA 35
RESTORE_USER_ALL 0x16 Restore entire operating memory from
EEPROM.
Send Byte N NA 35
CAPABILITY 0x19 Summary of PMBus optional
communication protocols supported by
this device.
R Byte N Reg 0xB0 35
VOUT_MODE 0x20 Output voltage data format and mantissa
exponent. (2
–13
)
R Byte Y Reg 0x13 35
VOUT_COMMAND 0x21 Servo Target. Nominal DC/DC converter
output voltage setpoint.
R/W Word Y L16 V Y 1.0
0x2000
36
VOUT_MAX 0x24
Upper limit on the output voltage the unit
can command regardless of any other
commands.
R/W Word Y L16 V Y 4.0
0x8000
36
VOUT_MARGIN_HIGH
0x25 Margin high DC/DC converter output
voltage setting.
R/W Word Y L16 V Y 1.05
0x219A
36
VOUT_MARGIN_LOW
0x26 Margin low DC/DC converter output
voltage setting.
R/W Word Y L16 V Y 0.95
0x1E66
36
VIN_ON 0x35
Input voltage (V
IN_SNS
) above which
power conversion can be enabled.
R/W Word N L11 V Y 10.0
0xD280
36
VIN_OFF 0x36
Input voltage (V
IN_SNS
) below which
power conversion is disabled. All V
OUT_EN
pins go off immediately.
R/W Word N L11 V Y 9.0
0xD240
36
VOUT_OV_FAULT_LIMIT 0x40 Output overvoltage fault limit R/W Word Y L16 V Y 1.1
0x2333
36
VOUT_OV_FAULT_
RESPONSE
0x41
Action to be taken by the device when an
output overvoltage fault is detected.
R/W Byte Y Reg Y 0x80 38
VOUT_OV_WARN_LIMIT 0x42 Output overvoltage warning limit . R/W Word Y L16 V Y 1.075
0x2266
36
VOUT_UV_WARN_LIMIT
0x43 Output undervoltage warning limit R/W Word Y L16 V Y 0.925
0x1D9A
36
VOUT_UV_FAULT_LIMIT
0x44 Output undervoltage fault limit. Limit
used to determine if TON_MAX_FAULT
has been met and the unit is on.
R/W W
ord Y L16 V Y 0.9
0x1CCD
36
VOUT_UV_FAULT_
RESPONSE
0x45
Action to be taken by the device when an
output undervoltage fault is detected.
R/W Byte Y Reg Y 0x7F 38
OT_FAULT_LIMIT 0x4F Overtemperature fault limit. R/W Word N L11 °C Y 105.0
0xEB48
37
OT_FAULT_RESPONSE
0x50 Action to be taken by the device when an
overtemperature fault is detected.
R/W Byte N Reg Y 0xB8 39