Linear Technology LTC2977 Demo Board: Octal Power Supply Manager [Requires DC1613] DC2028A DC2028A Data Sheet
Product codes
DC2028A
LTC2977
41
2977fa
STATUS COMMANDS
STATUS_BYTE
The STATUS_BYTE command returns the summary of the most critical faults or warnings which have occurred, as
The STATUS_BYTE command returns the summary of the most critical faults or warnings which have occurred, as
shown in the following table. STATUS_BYTE is a subset of STATUS_WORD and duplicates the same information.
STATUS_BYTE Data Contents
BIT(S) SYMBOL
OPERATION
b[7]
Status_byte_busy
Same as Status_word_busy
b[6]
Status_byte_off
Same as Status_word_off
b[5]
Status_byte_vout_ov
Same as Status_word_vout_ov
b[4]
Status_byte_iout_oc
Same as Status_word_iout_oc
b[3]
Status_byte_vin_uv
Same as Status_word_vin_uv
b[2]
Status_byte_temp
Same as Status_word_temp
b[1]
Status_byte_cml
Same as Status_word_cml
b[0]
Status_byte_high_byte
Same as Status_word_high_byte
STATUS_WORD
The STATUS_WORD command returns two bytes of information with a summary of the unit’s fault condition. Based on
The STATUS_WORD command returns two bytes of information with a summary of the unit’s fault condition. Based on
the information in these bytes, the host can get more information by reading the appropriate detailed status register.
The low byte of the STATUS_WORD is the same register as the STATUS_BYTE command.
The low byte of the STATUS_WORD is the same register as the STATUS_BYTE command.
STATUS_WORD Data Contents
BIT(S) SYMBOL
OPERATION
b[15]
Status_word_vout
An output voltage fault or warning has occurred. See STATUS_VOUT.
b[14]
Status_word_iout
Not supported. Always returns 0.
b[13]
Status_word_input
An input voltage fault or warning has occurred. See STATUS_INPUT.
b[12]
Status_word_mfr
A manufacturer specific fault has occurred. See STATUS_MFR_SPECIFIC and MFR_STATUS_2.
b[11]
Status_word_power_not_good
The PWRGD pin, if enabled, is negated. Power is not good.
b[10]
Status_word_fans
Not supported. Always returns 0.
b[9]
Status_word_other
Not supported. Always returns 0.
b[8]
Status_word_unknown
Not supported. Always returns 0.
b[7]
Status_word_busy
Device busy when PMBus command received. See OPERATION: Processing Commands.
b[6]
Status_word_off
This bit is asserted if the unit is not providing power to the output, regardless of the reason, including
simply not being enabled. The off bit is clear if unit is allowed to provide power to the output.
b[5]
Status_word_vout_ov
An output overvoltage fault has occurred.
b[4]
Status_word_iout_oc
Not supported. Always returns 0.
b[3]
Status_word_vin_uv
A V
IN
undervoltage fault has occurred.
b[2]
Status_word_temp
A temperature fault or warning has occurred. See STATUS_TEMPERATURE.
b[1]
Status_word_cml
A communication, memory or logic fault has occurred. See STATUS_CML.
b[0]
Status_word_high_byte
A fault/warning not listed in b[7:1] has occurred.
pMbus coMManD DescripTion