Datasheet

LTC2974
66
2974fc
For more information www.linear.com/LTC2974
This is the only command that may still be read when the LTC2974 is busy processing an EEPROM or other command.
It may be polled by the host to determine when the LTC2974 is available to process a PMBus command. A busy device
will always acknowledge its address but will NACK the command byte and set Status_byte_busy and Status_word_busy
when it receives a command that it cannot immediately process. ALERTB will not be asserted low in this case.
MFR_COMMON Data Contents
BIT(S) SYMBOL OPERATION
b[7] Mfr_common_alertb Returns alert status.
1: ALERTB is de-asserted high.
0: ALERTB is asserted low.
b[6] Mfr_common_busyb Returns device busy status.
1: The device is available to process PMBus commands.
0: The device is busy and will NACK PMBus commands.
b[5:2] Reserved Read only, always returns 1s.
b[1] Mfr_common_share_clk Returns the status of the share-clock pin.
1: Share-clock pin is being held low.
0: Share-clock pin is active.
b[0] Mfr_common_write_protect Returns the status of the write-protect pin.
1: Write-protect pin is high.
0: Write-protect pin is low.
pMbus coMManD DescripTion
TELEMETRY
COMMAND NAME
CMD
CODE DESCRIPTION TYPE PAGED FORMAT UNITS EEPROM
DEFAULT
VALUE
REF
PAGE
READ_VIN 0x88 Input supply voltage. R Word N L11 V NA
67
READ_VOUT 0x8B DC/DC converter output voltage. R Word Y L16 V NA
67
READ_IOUT 0x8C DC/DC converter output current. R Word Y L11 A NA
67
READ_TEMPERATURE_1 0x8D External diode junction temperature. This
is the value used for all temperature related
processing, including IOUT_CAL_GAIN.
R Word Y L11 °C NA
67
READ_TEMPERATURE_2 0x8E Internal junction temperature. R Word N L11 °C NA
67
READ_POUT 0x96 DC/DC converter output power. R Word Y L11 W NA
67
MFR_READ_IOUT 0xBB Alternate data format for READ_IOUT. One
LSB = 2.5mA.
R Word Y CF 2.5mA NA
67
MFR_IOUT_SENSE_VOLTAGE 0xFA Absolute value of VISENSEP – VISENSEM.
One LSB = 3.05µV.
R Word Y CF 3.05µV NA
68
MFR_VIN_PEAK 0xDE Maximum measured value of READ_VIN. R Word N L11 V NA
69
MFR_VOUT_PEAK 0xDD Maximum measured value of READ_VOUT. R Word Y L16 V NA
69
MFR_IOUT_PEAK 0xD7 Maximum measured value of READ_IOUT. R Word Y L11 A NA
69
MFR_TEMPERATURE_1_PEAK 0xDF Maximum measured value of READ_
TEMPERATURE_1.
R Word Y L11 °C NA
69
MFR_VIN_MIN 0xFC Minimum measured value of READ_VIN. R Word N L11 V NA
69
MFR_VOUT_MIN 0xFB Minimum measured value of READ_VOUT. R Word Y L16 V NA
69
MFR_IOUT_MIN 0xD8 Minimum measured value of READ_IOUT. R Word Y L11 A NA
69
MFR_TEMPERATURE_1_MIN 0xFD Minimum measured value of READ_
TEMPERATURE_1.
R Word Y L11 °C NA
69