LTC3882-1
98
Rev A
For more information
TON_MAX_FAULT_RESPONSE
The TON_MAX_FAULT_RESPONSE command instructs the device on what action to take in response to a TON_MAX
fault. The format for this command is given in Table 13. The device also:
• Sets the VOUT Bit in the STATUS_WORD
• Sets the TON_MAX_FAULT Bit in the STATUS_VOUT Command
• Notifies the Host by Asserting
ALERT
, Unless Masked
This command has one data byte.
Table 13. Data Byte Contents for the Following _FAULT_RESPONSE Commands: VIN_OV, OT, UT and TON_MAX
BITS
DESCRIPTION
VALUE
MEANING
[7:6]
For all values of bits [7:6], the LTC3882-1:
• Sets the corresponding fault bits in the status commands.
• Notifies the host by asserting
ALERT
, unless masked.
The fault, once set, is cleared only when one or more of the
following events occurs:
• The device receives a CLEAR_FAULTS command.
• The corresponding fault bit is written to a one.
• The output is commanded off, then on, by the RUN pin or
OPERATION command.
• The device receives a RESTORE_USER_ALL command.
• The device receives an MFR_RESET command.
• IC supply power is cycled.
00
The LTC3882-1 continues operating without interruption.
01
Not supported. Writing this value will generate a CML fault.
10
The LTC3882-1 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.
000-110
The LTC3882-1 does not attempt to restart. The output
remains disabled until the fault is cleared, the device is
commanded off and then on, or bias power is cycled.
111
The LTC3882-1 attempts to restart continuously without
limitation with an interval set by MFR_RETRY_DELAY.
This response persists until the unit is commanded off,
bias power is removed, or another fault response forces
shutdown without retry.
[2:0]
Delay time.
xxx
Not supported. Values ignored.
MFR_RETRY_DELAY
The MFR_RETRY_DELAY command sets the time in milliseconds between restart attempts for all retry fault responses.
The actual retry delay may be the longer of MFR_RETRY_DELAY or the time required for the output voltage to decay
below 12.5% of its programmed value. Decay qualification can be disabled using the MFR_CHAN_CONFIG_LTC3882-1
command. Retry delay starts once the fault is no longer detected by the LTC3882-1 or its
FAULT
pin is externally re-
leased. Legal values run from 120ms to 32.7 seconds.
This command has two data bytes in Linear_5s_11s format.
SMBALERT_MASK
The SMBALERT_MASK command can be used to prevent a particular status bit or bits from asserting
ALERT
as they
are asserted.
PMBus COMMAND DETAILS
(Fault Response and Communication)