102
Rev. B
For more information
PMBus COMMAND DETAILS
This condition is detected by the ADC so the response time may be up to t
CONVERT
.
This command has one data byte.
Table 19. Data Byte Contents: TON_MAX_FAULT_RESPONSE, VIN_OV_FAULT_RESPONSE,
OT_FAULT_RESPONSE, UT_FAULT_RESPONSE
BITS
DESCRIPTION
VALUE
MEANING
7:6
Response
For all values of bits [7:6], the LTM4680:
• Sets the corresponding fault bit in the status commands, and
• Notifies the host by asserting
ALERT
pin, unless masked.
The fault bit, once set, is cleared only when one or more of the
following events occurs:
• The device receives a CLEAR_FAULTS command.
• 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
• The device receives a RESTORE_USER_ALL command.
• The device receives a MFR_RESET command.
• The device supply power is cycled.
00
The PMBus device continues operation without interruption.
01
Not supported. Writing this value will generate a CML fault.
10
The device shuts down immediately (disables the output) and
responds according to the retry setting in bits [5:3].
11
Not supported. Writing this value will generate a CML fault.
5:3
Retry Setting
000
The unit does not attempt to restart. The output remains
disabled until the fault is cleared until the device is commanded
OFF bias power is removed.
111
The PMBus device attempts to restart continuously, without
limitation, until it is commanded OFF (by the RUN pin or
OPERATION command or both), bias power is removed, or
another fault condition causes the unit to shut down without
retry. Note: The retry interval is set by the MFR_RETRY_DELAY
command.
2:0
Delay Time
XXX
Not supported. Values ignored
FAULT SHARING
Fault Sharing Propagation
COMMAND NAME
CMD CODE DESCRIPTION
TYPE
PAGED
DATA
FORMAT UNITS
NVM
DEFAULT
VALUE
MFR_FAULT_
PROPAGATE
0xD2
Configuration that determines which faults
are propagated to the FAULT pins.
R/W Word
Y
Reg
Y
0x6993
MFR_FAULT_PROPAGATE
The MFR_FAULT_PROPAGATE command enables the faults that can cause the
FAULT
n
pin to assert low. The com-
mand is formatted as shown in Table 20. Faults can only be propagated to the
FAULT
n
pin if they are programmed to
respond to faults.
This command has two data bytes.