LTC3882_15 Datasheet, PDF (95/104 Pages) Linear Technology – Dual Output PolyPhase Step-Down DC/DC Voltage Mode Controller with Digital Power System Management

LTC3882
PMBus COMMAND DETAILS (Fault Response and Communication)
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:
00 The LTC3882 continues operating without interruption.
• 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.
01 Not supported. Writing this value will generate a CML fault.
10 The LTC3882 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 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 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
command. Retry delay starts once the fault is no longer detected by the LTC3882 or its GPIO pin is externally released.
Legal values run from 120ms to 32.7 seconds.
This command has two data bytes in Linear_5s_11s format.
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