Vout_trim, Vout_cal_offset, Vout_max – Maxim Integrated MAX15303 PMBus Command Set User Manual
Page 10: Vout_margin_high
MAX15303 PMBus Command Set User’s Guide
Page 10 of 52
VOUT_TRIM
, and the result is sent to the control loop as the output voltage setpoint.
Note that in the MAX15303, VOUT_TRIM is sent as a PMBus Linear value, rather than as a two’s
complement binary integer mantissa as specified in the PMBus standard, to avoid introducing
another numeric format.
The value of VOUT_TRIM is not subtracted from READ_VOUT, so non-zero VOUT_TRIM values will
result in a difference between VOUT_COMMAND and READ_VOUT.
This command is intended to allow an end user of a PMBus device to tailor a specific supply to the
performance requirements of a specific load device, while retaining use of a “nominal” voltage
setpoint for all similar load devices.
VOUT_CAL_OFFSET
Reference:
Standard Command
Lockable:
Yes
Command Code:
0x23
Format:
Linear
Data Bytes:
2
Units:
V
Transfer:
Read/Write Word
Factory Value:
0x0000 (0V)
Description/Notes: See Section 13.4 of the PMBus Specification Part II.
In the MAX15303, the value of VOUT_CAL_OFFSET is summed with the value of
and
, and the result is sent to the control loop as the output voltage setpoint.
Note that in the MAX15303, VOUT_CAL_OFFSET is sent as a PMBus Linear value, rather than as a
two’s complement binary integer mantissa as specified in the PMBus standard, to avoid introducing
another numeric format.
The value of VOUT_CAL_OFFSET is subtracted from READ_VOUT, so VOUT_CAL_OFFSET values never
result in a difference between VOUT_COMMAND and READ_VOUT.
This command is intended to allow a PMBus device manufacturer or an end user to calibrate the
output voltage of a module (or other power-supply assembly) to match an external reference
instrument during their final-test process.
VOUT_MAX
Reference:
Standard Command
Lockable:
Yes
Command Code:
0x24
Format:
Unsigned integer mantissa
Data Bytes:
2
Units:
V
Transfer:
Read/Write Word
Factory Value:
0x5001 (5.000V)
Description/Notes: See Section 13.5 of the PMBus Specification Part II.
VOUT_MAX mantissa data sent to and from the MAX15303 must be divided by 4096 to determine the
actual voltage value, according to the fixed value of
The factory value of 0x5001 (5.000V) will be overridden during initialization to
x 1.15, unless a specific value has been written to the User Store.