L6751 Datasheet, PDF (50/59 Pages) STMicroelectronics – Digitally controlled dual PWM for Intel VR12 and AMD SVI

PMBus support (preliminary)
12 PMBus support (preliminary)
L6751
The L6751 is compatible with PMBus™ standard revision 1.1, refer to PMBus standard
documentation for further information (www.pmbus.org).
Table 16. Supported commands
Command
Per Code
Rail [Hex]
Mode
Comments
OPERATION
Used to turn the controller on/off in conjunction with the input
Y
01 RW Byte from the control pin. Also used to set margin voltages. Soft off
not supported
ON_OFF_CONFIG
N1
02
RW Byte
Configures how the controller responds when power is
applied
WRITE_PROTECT
Y
10
RW Byte
Controls writing to the PMBus device to prevent accidental
changes
VOUT_COMMAND
Y
21
RW Word
Causes the converter to set its output voltage to the
commanded value - VID mode
VOUT_MAX
Y
VOUT_MARGIN_HIGH Y
24
RW Word
Sets the upper limit on the output voltage regardless of any
other command
25
RW Word
Sets the voltage to which the output is to be changed when
the OPERATION command is set to “margin high”
VOUT_MARGIN_LOW Y
26
RW Word
Sets the voltage to which the output is to be changed when
the OPERATION command is set to “margin low”
IOUT_CAL_OFFSET Y
39 RW Word Calibration for IOUT reading
OT_FAULT_LIMIT
OT_WARN_LIMIT
Y
4F RW Word Overtemperature fault threshold
Y
51 RW Word Overtemperature warning threshold
VIN_OV_FAULT_LIMIT N
55 RW Word Input voltage monitor overvoltage limit
VIN_UV_FAULT_LIMIT N
59 RW Word Input voltage monitor undervoltage limit
MFR_SPECIFIC_01
N
D1
RW Byte
AVERAGE_TIME_SCALE. Sets the time between two
measurements
MFR_SPECIFIC_02
Y
D2
RW Byte
DEBUG_MODE. [01/10] Switches [ON/OFF] the Vout control
on PMBus domain
MFR_SPECIFIC_05
MFR_SPECIFIC_08
Y
D5
RW Byte
VOUT_TRIM. Used to apply a fixed offset voltage to the
output voltage command value
Y D8 RW Byte VOUT_DROOP. Used to change the Vout droop
MFR_SPECIFIC_35
MFR_SPECIFIC_38
N1
F3
RW Byte
MANUAL_PHASE_SHEDDING. Used to manage the phase
shedding manually
Y
F6
RW Byte
VOUT_OV_FAULT_LIMIT. Allows the OV protection threshold
to be programmed for each rail
MFR_SPECIFIC_39
MFR_SPECIFIC_40
Y
F7 RW Byte VFDE_ENABLE
Y
F8 RW Byte ULTRASONIC_ENABLE
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Doc ID 023992 Rev 1