Datasheet

LTC2978A
24
2978afa
For more information www.linear.com/LTC2978A
Processing Commands
The LTC2978A uses a dedicated processing block to ensure quick response to all of its commands. There are a few
exceptions where the part will NACK a subsequent command because it is still processing the previous command.
These are summarized in the following tables.
EEPROM Related Commands
COMMAND TYPICAL DELAY* COMMENT
STORE_USER_ALL t
MASS_WRITE
See Electrical Characteristics table. The LTC2978A will not accept any commands while it is
transferring register contents to the EEPROM. The command byte will be NACKed.
RESTORE_USER_ALL 30ms The LTC2978A will not accept any commands while it is transferring EEPROM data to command
registers. The command byte will be NACKed.
MFR_FAULT_LOG_CLEAR 175ms The LTC2978A will not accept any commands while it is initializing the fault log EEPROM space. The
command byte will be NACKed.
MFR_FAULT_LOG_STORE 20ms The LTC2978A will not accept any commands while it is transferring the fault log RAM buffer to
EEPROM space. The command byte will be NACKed.
Internal Fault log 10ms An internal fault log event is a one time event that uploads the contents of the fault log to EEPROM
in response to a fault. Internal fault logging may be disabled. Commands received during this
EEPROM write are NACKed.
MFR_FAULT_LOG_RESTORE 2ms The LTC2978A will not accept any commands while it is transferring EEPROM data to the fault log
RAM buffer. The command byte will be NACKed.
*The typical delay is measured from the command
’s stop to the next command’s start.
COMMAND TYPICAL DELA
Y* COMMENT
MFR_CONFIG_LT C 2978 <50µs The LTC2978A will not accept any commands while it is completing this command. The command
byte will be NACKed.
*The typical delay is measured from the command’s stop to the next command’s start.
Other PMBus Timing Notes
COMMAND COMMENT
CLEAR_FAULTS The LTC2978A will accept commands while it is completing this command but the affected status flags will not be cleared
for up to 500µs.
OPERATION