LTC3882_15 Datasheet, PDF (93/104 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)
IOUT_OC_FAULT_RESPONSE
The IOUT_OC_FAULT_RESPONSE command instructs the device on what action to take in response to an output
overcurrent fault. The device also:
• Sets the IOUT_OC Bit in the STATUS_BYTE
• Sets the IOUT Bit in the STATUS_WORD
• Sets the I_OUT Overcurrent Fault Bit in the STATUS_IOUT Command
• Notifies the Host by Asserting ALERT
Output overcurrent faults are ignored during TON_RISE and TOFF_FALL output sequencing.
Data Byte Contents for IOUT_OC_FAULT_RESPONSE:
BITS DESCRIPTION
[7:6] For all values of bits [7:6], the LTC3882:
• 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 STATUS_IOUT 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.
[5:3] Retry setting.
[2:0] Delay time.
VALUE
0x
10
11
MEANING
The LTC3882 continues to operate indefinitely with the
normal hardware response described in the Operation
section.
The LTC3882 continues operating with the normal hardware
response for the delay time specified by bits [2:0]. If the
fault is continuously present for the entire delay, the unit
then disables the output and does not attempt to restart.
The LTC3882 shuts down (disables the output) and
responds according to the retry setting in bits [5:3].
000-110
111
xxx
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.
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.
Response delay time in 16ms increments. This delay time
determines how long the fault may have to persist before
the controller is disabled, depending on bits [7:6]. These
bits always return zero if bits [7:6] are not set to 0x2.
Programming an unsupported IOUT_OC_FAULT_RESPONSE value will generate a CML fault and the command will
be ignored.
This command has one data byte.
For more information www.linear.com/LTC3882
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