Datasheet

LTC2974
30
2974fc
For more information www.linear.com/LTC2974
OPERATION
The OPERATION command is used to turn the unit on and off in conjunction with the CONTROL pin and ON_OFF_CON-
FIG. This command register responds to the global page command (PAGE=0xFF). The contents and functions of the
data byte are shown in the following tables. A minimum t
OFF_MIN
wait time must be observed between any OPERATION
commands used to turn the unit off and then back on to give the ADC telemetry loop time to complete a full cycle.
OPERATION Data Contents (On_off_config_use_pmbus=1)
SYMBOL Action Operation_control[1:0] Operation_margin[1:0] Operation_fault[1:0] Reserved (read only)
BITS b[7:6] b[5:4] b[3:2] b[1:0]
FUNCTION
Turn off immediately 00 XX XX 00
Sequence on 10 00 XX 00
Margin low (ignore faults and
warnings)
10 01 01 00
Margin low 10 01 10 00
Margin high (ignore faults and
warnings
10 10 01 00
Margin high 10 10 10 00
Sequence off with margin to
nominal
01 00 XX 00
Sequence off with margin low
(ignore faults and warnings)
01 01 01 00
Sequence off with margin low 01 01 10 00
Sequence off with margin high
(ignore faults and warnings)
01 10 01 00
Sequence off with margin high 01 10 10 00
Reserved All remaining combinations
pMbus coMManD DescripTion
ON/OFF CONTROL, MARGINING AND CONFIGURATION
COMMAND NAME
CMD
CODE DESCRIPTION TYPE PAGED FORMAT UNITS EEPROM
DEFAULT
VALUE
REF
PAGE
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
31
MFR_CONFIG_LTC2974 0xD0 Configuration bits that are channel
specific.
R/W Word Y Reg Y 0x0080
32
MFR_CONFIG2_LTC2974
0xD9 Configuration bits that are channel
specific
R/W Byte N Reg Y 0x00
35
MFR_CONFIG3_LTC2974
0xDA Configuration bits that are channel
specific
R/W Byte N Reg Y 0x00
35
MFR_CONFIG_ALL_LTC2974 0xD1 Configuration bits that are common to all
pages.
R/W Word N Reg Y 0x0F7B
39