ltc2978 Linear Technology Corporation, ltc2978 Datasheet - Page 30

• Manufacturer Part Number: ltc2978
• Description: Octal Pmbus Power Supply Monitor And Controller With Eeprom
• Manufacturer: Linear Technology Corporation

Timed Fault Response
TON_MAX_FAULT_RESPONSE
This command defines the LTC2978 response to a
TON_MAX_FAULT. At start-up, the TON_MAX_FAULT_
RESPONSE is disarmed once the output voltage reaches
the VOUT_UNDER_VOLTAGE_LIMIT. The only way to
protect against a short-circuited output at start-up is
to take action in response to a TON_MAX_FAULT since
VOUT_UV_FAULT_RESPONSE is not armed until the output
reaches the VOUT_UNDER_VOLTAGE_LIMIT.
TON_MAX_FAULT_RESPONSE Data Contents
LTC2978
operaTion
0
BIT(S) SYMBOL
b[7:6] Ton_max_fault_response_action Response action.
b[5:3] Ton_max_fault_response_retry
b[2:0] Ton_max_fault_response_delay
OPERATION
2’b00: The unit continues operation without interruption.
2’b01: The unit continues operating for the delay time specified which for this type of fault corresponds to an
immediate shutdown. After shutting off, the device responds according to the retry settings in bits [5:3].
2’b1X: The device shuts down and responds according to the retry setting in bits [5:3].
Response action:
3’b000: 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.
3’b001-111: The PMBus device attempts to restart continuously, without limitation, using Mfr_retry_delay,
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.
Hard coded to 3’b000. The unit turns off immediately.
The device also:
• Sets the HIGH_BYTE bit in the STATUS_BYTE,
• Sets the VOUT bit in the STATUS_WORD,
• Sets the TON_MAX_FAULT bit in the STATUS_VOUT
• Notifies the host by asserting ALERTB.
register, and
2978fa