Datasheet

LTC2974
22
2974fc
For more information www.linear.com/LTC2974
Summary Table
COMMAND NAME
CMD
CODE DESCRIPTION TYPE PAGED
DATA
FORMAT UNITS EEPROM
DEFAULT
VALUE:
FLOAT
HEX
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
30
ON_OFF_CONFIG 0x02 CONTROL pin and PMBus on/off
command setting.
R/W Byte Y Reg Y 0x12
30
CLEAR_FAULTS 0x03 Clear any fault bits that have been set. Send Byte Y NA
61
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
40
RESTORE_USER_ALL 0x16 Restore entire operating memory from
EEPROM.
Send Byte N NA
40
CAPABILITY 0x19 Summary of PMBus optional
communication protocols supported by
this device.
R Byte N Reg 0xB0
78
VOUT_MODE 0x20 Output voltage data format and mantissa
exponent (2
–13
).
R Byte Y Reg 0x13
44
VOUT_COMMAND 0x21 Servo target. Nominal DC/DC converter
output voltage setpoint.
R/W Word Y L16 V Y 1.0
0x2000
44
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
44
VOUT_MARGIN_HIGH 0x25 Margin high DC/DC converter output
voltage setting.
R/W Word Y L16 V Y 1.05
0x219A
44
VOUT_MARGIN_LOW 0x26 Margin low DC/DC converter output
voltage setting.
R/W Word Y L16 V Y 0.95
0x1E66
44
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
43
VIN_OFF 0x36 Input voltage (V
IN_SNS
) below which
power conversion is disabled. All V
OUT_EN
pins go off immediately or sequence off
after TOFF_DELAY (See Mfr_config_track_
enn).
R/W Word N L11 V Y 9.0
0xD240
43
IOUT_CAL_GAIN 0x38 The nominal resistance of the current
sense element in mΩ.
R/W Word Y L11 mΩ Y 1.0
0xBA00
46
VOUT_OV_FAULT_LIMIT 0x40 Output overvoltage fault limit. R/W Word Y L16 V Y 1.1
0x2333
44
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
54
VOUT_OV_WARN_LIMIT 0x42 Output overvoltage warning limit. R/W Word Y L16 V Y 1.075
0x2266
44
VOUT_UV_WARN_LIMIT 0x43 Output undervoltage warning limit. R/W Word Y L16 V Y 0.925
0x1D9A
44
VOUT_UV_FAULT_LIMIT 0x44 Output undervoltage fault limit. Used for
Ton_max_fault and power good de-
assertion.
R/W Word Y L16 V Y 0.9
0x1CCD
44
pMbus coMManD suMMary
Note: The data format abbreviations are detailed at the end of this table