Datasheet

LTC2978A
54
2978afa
For more information www.linear.com/LTC2978A
MFR_SPECIAL_LOT
These paged registers contain information that identifies the user configuration that was programmed at the factory.
MFR_SPECIAL_LOT Data Contents
BIT(S) SYMBOL OPERATION
b[7:0] Mfr_special_lot Contains the LT C default special lot number. Contact the factory to request a custom factory programmed user configu-
ration and special lot number.
MFR_VOUT_DISCHARGE_THRESHOLD
This register contains the coefficient that multiplies VOUT_COMMAND in order to determine the OFF threshold
voltage for the associated output. If the output voltage has not decayed below MFR_VOUT_DISCHARGE_
THRESHOLD • VOUT_COMMAND prior to the channel being commanded to enter/re-enter the ON state, the Status_
mfr_discharge bit in the STATUS_MFR_SPECIFIC register will be set and the ALERTB pin will be asserted low. In
addition, the channel will not enter the ON state until the output has decayed below its OFF threshold voltage. Setting
this to a value greater than 1.0 effectively disables DISCHARGE_THRESHOLD checking, allowing the channel to turn
back on even if it has not decayed at all.
Other channels can be held off if a particular output has failed to discharge by using the bidirectional FAULTBzn pins
(refer to the MFR_FAULTBzn_RESPONSE and MFR_FAULTBzn_PROPAGATE registers).
MFR_VOUT_DISCHARGE_THRESHOLD Data Contents
BIT(S) SYMBOL OPERATION
b[15:0] Mfr_vout_discharge_
threshold
The data uses the L11 format.
Units: Dimensionless, this register contains a coefficient.
MFR_COMMON
This command returns status information for the share-clock pin (SHARE_CLK) and the write-protect pin (WP).
MFR_COMMON Data Contents
BIT(S) SYMBOL OPERATION
b[7:2] Reserved Read only, always returns 0s
b[1] Mfr_common_
share_clk
Returns status of share-clock pin
1: Share-clock pin is being held low
0: Share-clock pin is active
b[0] Mfr_common_
write_protect
Returns status of write-protect pin
1: Write-protect pin is high
0: Write-protect pin is low
MFR_SPARE_0, MFR_SPARE_1, MFR_SPARE_2, MFR_SPARE_3
These registers are provided as user scratchpad and additional manufacturer reserved locations.
MFR_SPARE_1 and MFR_SPARE_3 are all reserved for manufacturer use. Such uses include manufacturer traceability
information and LTpowerPlay features like the CRC calculation and storage for user EEPROM configurations.
MFR_SPARE_0 and MFR_SPARE_2 are available for user scratchpad use. These 18 bytes (1 unpaged word plus 8
paged words) might be used for traceability or revision information such as serial number, board model number, as-
sembly location, or assembly date.
PMBus COMMAND DESCRIPTION