Datasheet

LTC2974
57
2974fc
For more information www.linear.com/LTC2974
OT_FAULT_RESPONSE, UT_FAULT_RESPONSE, VIN_OV_FAULT_RESPONSE and VIN_UV_FAULT_RESPONSE
The fault response documented here is for values that are measured by the ADC. Note that in addition to the response
described by these commands, the LTC2974 will also:
• Set the appropriate bit(s) in the STATUS_BYTE.
• Set the appropriate bit(s) in the STATUS_WORD.
• Set the appropriate bit in the corresponding STATUS_VIN or STATUS_TEMPERATURE register, and
• Notify the host by pulling the ALERTB pin low.
OT_FAULT_RESPONSE, UT_FAULT_RESPONSE, VIN_OV_FAULT_RESPONSE, VIN_UV_FAULT_RESPONSE Data Contents
BIT(S) SYMBOL OPERATION
b[7:6] Ot_fault_response_action,
Ut_fault_response_action,
Vin_ov_fault_response_action,
Vin_uv_fault_response_action
Response action:
00b: The unit continues operation without interruption.
01b-11b: The unit shuts down immediately or sequences off after TOFF_DELAY (See Mfr_config_track_enn).
After shutting down, the device responds according to the retry settings in bits [5:3].
b[5:3] Ot_fault_response_retry,
Ut_fault_response_retry,
Vin_ov_fault_response_retry,
Vin_uv_fault_response_retry
Response retry behavior:
000b: A zero value for the retry setting means that the unit does not attempt to restart. The output remains
disabled until the fault is cleared.
001b-111b: The PMBus device attempts to restart the number of times specified by the global Mfr_retry_
count[2:0] until it is commanded OFF (by the CONTROL pin or OPERATION command or both), bias power is
removed, or another fault condition causes the unit to shut down.
Changing the value might not take effect until the next off-then-on sequence on that channel.
b[2:0] Ot_fault_response_delay,
Ut_fault_response_delay,
Vin_ov_fault_response_delay,
Vin_uv_fault_response_delay
Hard coded to 000b: There is no additional deglitch delay applied to fault detection.
pMbus coMManD DescripTion