Datasheet

LTC2977
50
2977fa
For more information www.linear.com/LTC2977
MFR_CONFIG_ALL_LT C 2977 Data Contents
BIT(S) SYMBOL OPERATION
b[2] Mfr_config_all_pec_en PMBus packet error checking enable.
0: PEC is accepted but not required
1: PEC is required
b[1] Mfr_config_all_longer_pmbus_
timeout
Increase PMBus timeout internal by a factor of 8. Recommended for fault logging.
0: PMBus timeout is not multiplied by a factor of 8
1: PMBus timeout is multiplied by a factor of 8
b[0] Mfr_config_all_vinen_wpu_dis V
IN_EN
charge-pumped, current-limited pull-up disable.
0: Use weak current-limited pull-up on V
IN_EN
after power-up, as long as no faults have forced V
IN_EN
off.
1: Disable weak pull-up. V
IN_EN
driver is three-stated after power-up as long as no faults have forced
V
IN_EN
off.
MFR_FAULTBz0_PROPAGATE, MFR_FAULTBz1_PROPAGATE
These manufacturer specific commands enable channels that have faulted off to propagate that state to the appropri-
ate fault
pin. Faulted off states for pages 0 through 3 can only be propagated to pins FAULTB00 and FAULTB01; this is
referred
to as zone 0. Faulted off states for pages 4 through 7 can only be propagated to pins FAULTB10 and FAULTB11;
this is referred to as zone 1. The z designator in
the command
name is used to indicate that this command affects
different zones depending on the page. See Figure 20.
Note that pulling a fault pin low will have no effect for channels that have MFR_FAULTBzn_RESPONSE set to 0. The
channel continues operation without interruption. This fault response is called Ignore (0x0) in LTpowerPlay.
MFR_FAULTBz0_PROPAGATE Data Content
BIT(S) SYMBOL OPERATION
b[7:1] Reserved Don’t care. Always returns 0.
b[0] Mfr_faultbz0_propagate Enable fault propagation.
For pages 0 through 3, zone 0
0: Channel’s faulted off state does not assert FAULTB00 low.
1: Channel’s faulted off state asserts FAULTB00 low.
For pages 4 through 7, zone 1
0: Channel’s faulted off state does not assert FAULTB10 low.
1: Channel’s faulted off state asserts FAULTB10 low.
MFR_FAULTBz1_PROPAGATE Data Content
BIT(S) SYMBOL OPERATION
b[7:1] Reserved Don’t care. Always returns 0.
b[0] Mfr_faultbz1_propagate Enable fault propagation.
For pages 0 through 3, zone 0
0: Channel’s faulted off state does not assert FAULTB01 low.
1: Channel’s faulted off state asserts FAULTB01 low.
For pages 4 through 7, zone 1
0: Channel’s faulted off state does not assert FAULTB11 low.
1: Channel’s faulted off state asserts FAULTB11 low.
PMBus COMMAND DESCRIPTION