Datasheet

LTC2974
61
2974fc
For more information www.linear.com/LTC2974
CLEAR_FAULTS
The CLEAR_FAULTS command is used to clear status bits that have been set. This command clears all fault and warn-
ing bits in all unpaged status registers, and paged status registers selected by the current PAGE setting. At the same
time, the device negates (clears, releases) its contribution to ALER
TB.
The CLEAR_FAULTS command does not cause a unit that has latched off for a fault condition to restart. See Clearing
Latched Faults for more information.
If the fault is present after the fault is cleared, the fault status bit shall be set again and the host notified by the usual
means.
Note: this command responds to the global page command. (P
AGE=0xFF)
STATUS_BYTE
The STATUS_BYTE command returns the summary of the most critical faults or warnings which have occurred, as
shown in the following table. STATUS_BYTE is a subset of STATUS_WORD and duplicates the same information.
STATUS_BYTE Data Contents
BIT(S) SYMBOL OPERATION
b[7] Status_byte_busy Same as Status_word_busy.
b[6] Status_byte_off Same as Status_word_off.
b[5] Status_byte_vout_ov Same as Status_word_vout_ov.
b[4] Status_byte_iout_oc Same as Status_word_iout_oc.
b[3] Status_byte_vin_uv Same as Status_word_vin_uv.
b[2] Status_byte_temp Same as Status_word_temp.
b[1] Status_byte_cml Same as Status_word_cml.
b[0] Status_byte_high_byte Same as Status_word_high_byte.
pMbus coMManD DescripTion
FAULT WARNING AND STATUS
COMMAND NAME
CMD
CODE DESCRIPTION TYPE PAGED FORMAT UNITS EEPROM
DEFAULT
VALUE
REF
PAGE
CLEAR_FAULTS 0x03 Clear any fault bits that have been set. Send Byte Y NA
61
STATUS_BYTE 0x78 One byte summary of the unit’s fault condition. R Byte Y Reg NA
61
STATUS_WORD 0x79 Two byte summary of the unit’s fault condition. R Word Y Reg NA
62
STATUS_VOUT 0x7A Output voltage fault and warning status. R Byte Y Reg NA
62
STATUS_IOUT 0x7B Output current fault and warning status. R Byte Y Reg NA
63
STATUS_INPUT 0x7C Input supply fault and warning status. R Byte N Reg NA
63
STATUS_TEMPERATURE 0x7D External temperature fault and warning status
for READ_TEMPERATURE_1.
R Byte Y Reg NA
63
STATUS_CML 0x7E Communication and memory fault and warning
status.
R Byte N Reg NA
64
STATUS_MFR_SPECIFIC 0x80 Manufacturer specific fault and state
information.
R Byte Y Reg NA
64
MFR_PADS 0xE5 Current state of selected digital I/O pads. R/W Word N Reg NA
65
MFR_COMMON 0xEF Manufacturer status bits that are common
across multiple LTC chips.
R Byte N Reg NA
65