LTC3883 Datasheet, PDF (93/112 Pages) Linear Technology – Single Phase Step-Down DC/DC Controller with Digital Power System Management

LTC3883/LTC3883-1
PMBus Command Details
CLEAR_FAULTS
The CLEAR_FAULTS command is used to clear any fault bits that have been set. This command clears all bits in all
status commands simultaneously. At the same time, the device negates (clears, releases) its ALERT pin signal output
if the device is asserting the ALERT pin signal.
The CLEAR_FAULTS does not cause a unit that has latched off for a fault condition to restart. Units that have shut down
for a fault condition are restarted when:
• The output is commanded through the RUN pin, the OPERATION command, or the combined action of the RUN pin
and OPERATION command, to turn off and then to turn back on, or
• MFR_RESET command is issued.
• Bias power is removed and reapplied to the integrated circuit
If the fault is still present when the bit is cleared, the fault bit will remain set and the host notified by asserting the
ALERT pin pin low.
This write-only command has no data bytes.
MFR_CLEAR_PEAKS
The MFR_CLEAR_PEAKS command clears the MFR_*_PEAK data values. The MFR_RESET command will initiate this
command.
This write-only command has no data bytes.
STATUS_BYTE
The STATUS_BYTE command returns one byte of information with a summary of the most critical faults. This is the
lower byte of the status word.
The following status bits can be cleared by writing a 1 to their position in the STATUS_BYTE command:
[7] BUSY
This permits the user to clear status by means other than using the CLEAR_FAULTS command. This is also the only
bit of this command that can initiate an ALERT event.
[6] Bit 6 of this command will be set whenever the PWM is turned off. Setting this bit does not assert ALERT.
This command has one data byte.
STATUS_WORD
The STATUS_WORD command returns two bytes of information with a summary of the unit’s fault condition.
The following status bits can be cleared by writing a 1 to their position in the STATUS_WORD command:
[8] UNKNOWN
[7] BUSY
This permits the user to clear status by means other than using the CLEAR_FAULTS command. These are also the only
bits of this command that can initiate an ALERT event.
[6] Bit 6 of this command will be set whenever the output is turned off.
[11] Bit 11 of this command will be set whenever the output voltage is below the POWER_GOOD_OFF threshold.
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