Datasheet

LTC2977

2977fa

For more information www.linear.com/LTC2977

PMBus

COMMAND DESCRIPTION

MFR_RETRY_COUNT

The MFR_RETRY_COUNT is a global command that sets the number of retries attempted when any channel faults off

with its fault response retry field set to a non zero value.

In the event of multiple or recurring retry faults on the same channel the total number of retries equals MFR_RETRY_

COUNT. If a channel has not been faulted off for 6 seconds, its retry counter is cleared. Toggling a channel’s CONTROL

pin off then on or issuing OPERATION off then on commands will synchronously clear the retry count. Writing to

MFR_RETRY_COUNT clears the retry count for all channels

MFR_RETRY_COUNT Data Contents

BIT(S) SYMBOL OPERATION

b[7:3] Reserved Always returns zero.

b[2:0] Mfr_retry_count [2:0] 0: No retries:

1-6: Number of retries.

7: Infinite retries.

MFR_RETRY_DELAY

This command determines the retry interval when the LTC2977 is in retry mode in response to a fault condition. The read

value of this command always returns what was last written and does not reflect internal limiting.

MFR_RETRY_DELAY Data Contents

BIT(S) SYMBOL OPERATION

b[15:0] Mfr_retry_delay The data uses the L11 format.

This delay is counted using SHARE_CLK only.

Delays are rounded to the nearest 200µs.

Units: ms. Max delay is 13.1 sec.

MFR_RESTART_DELAY

This command sets the minimum off time of a CONTROL initiated restart. If the CONTROL pin is toggled off for at least 10µs

then on, all dependent channels are disabled, held off for a time = Mfr_restart_delay, then sequenced back on. CONTROLn

pin transitions whose OFF time exceeds Mfr_restart_delay are not affected by this command. A value of all zeros disables

this feature. The read value of this command always returns what was last written and does not reflect internal limiting.

MFR_RESTART_DELAY Data Contents

BIT(S) SYMBOL OPERATION

b[15:0] Mfr_restart_delay The data uses the L11 format.

This delay is counted using SHARE_CLK only.

Delays are rounded to the nearest 200µs.

Units: ms. Max delay is 13.1 sec.