LTC3815_15 Datasheet, PDF (35/42 Pages) Linear Technology – 6A Monolithic Synchronous DC/DC Step-Down Converter with Digital Power System Management

LTC3815
PMBus Command Details
This command has two data bytes and is formatted as a
9-bit 2’s complement number with 0.1%/bit scaling.
The range of MFR_VOUT_COMMAND value is limited to
±25%.
Do not attempt to write values outside of this range or
unpredictable behavior may result. Writes to this register
are inhibited when the WP pin is high.
MFR_ VOUT_MARGIN_LOW
The MFR_VOUT_MARGIN_LOW command loads the
LTC3815 with the value to which the output is changed, in
percent, when the OPERATION command is set to margin
low or the fast margining pin, MARGIN, is pulled below
0.4V. Slew rate limiting is same as MFR_VOUT_COMMAND.
This command has two data bytes and is formatted as a
9-bit 2’s complement number with 0.1%/bit scaling.
The range of MFR_VOUT_MARGIN_LOW value is limited
to ±25%. There is no restriction on the value relative to
VOUT_COMMAND and MFR_VOUT_MARGIN_HIGH, i.e.
the value is not required to be lower.
Do not attempt to write values outside of this range or
unpredictable behavior may result. Writes to this register
are inhibited when the WP pin is high.
MFR_VOUT_MARGIN_HIGH
The MFR_VOUT_MARGIN_LOW command loads the
LTC3815 with the value to which the output is changed, in
percent, when the OPERATION command is set to margin
high or the fast margining pin, MARGIN, is pulled above
1.1V. Slew rate limiting is same as MFR_VOUT_COMMAND.
This command has two data bytes and is formatted as a
9-bit 2’s complement number with 0.1%/bit scaling.
The range of MFR_VOUT_MARGIN_HIGH value is limited
to ±25%. There is no restriction on the value relative to
MFR_VOUT_COMMAND and MFR_VOUT_MARGIN_LOW,
i.e. the value is not required to be higher.
Do not attempt to write values outside of this range or
unpredictable behavior may result. Writes to this register
are inhibited when the WP pin is high.
PMBus_REVISION
The PMBUS_REVISION command indicates the revision of
the PMBus to which the device is compliant. The LTC3815
is PMBus Version 1.2 compliant in both Part I and Part II.
This read-only command has one data byte.
MFR_SPECIAL_ID
The 16-bit word representing the part name and revision.
The MSB equals 0x80 and denotes the part is an LTC3815.
The LSB is adjustable by the manufacturer.
This read-only command has 2 data bytes.
MFR_CLEAR_PEAKS
The MFR_CLEAR_PEAKS command clears the MFR_*_
PEAK data values and restarts the peak monitor routine.
This write-only command requires no data bytes, but will
accept (and ignore) up to two.
STATUS_WORD
The STATUS_WORD command returns two bytes of
information with a summary of the unit’s fault condition.
See Table 8 for a list of the status bits that are supported
and the conditions in which each bit is set. Certain bits
when set in the STATUS_WORD also cause the ALERT
pin to be asserted.
Writing a "1" to a particular bit in the status word will at-
tempt to reset that fault in the status word and the ALERT
pin. If the fault is still present the status word bit and
ALERT will remain asserted. If the ALERT has previously
been cleared by an ARA message, the ALERT will be re-
asserted. If the fault is no longer present, the ALERT pin
will be de-asserted and the fault bit in the status word
will be cleared.
All bits in the status word are also cleared by toggling the
RUN_MSTR pin or the ON bit in OPERATION. The bit will
immediately be set again if the fault remains.
This command has two data bytes.
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