Linear Technology LTC2977 Demo Board: Octal Power Supply Manager [Requires DC1613] DC2028A DC2028A Data Sheet

LTC2977

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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. These values are measured over a 

longer period of time and are not deglitched. Note that in addition to the response described by these commands, the 

LTC2977 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.

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 to 11b: The unit shuts down immediately or sequences off after TOFF_DELAY (See Mfr_config_chan_

mode). After shutting down, the unit responds according to the retry setting 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 CONTROLn pin or OPERATION command or both), bias power is 

removed, or another fault condition causes the unit to shut down.

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.