Datasheet

MAX34451 PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
www.maximintegrated.com
Maxim Integrated │ 36
IOUT_CAL_GAIN (38h)
TheIOUT_CAL_GAINcommandisusedtosettheratio
of the voltage at theADC input to the sensed current.
TheunitsoftheIOUT_CAL_GAINfactorare0.1mΩ.The
2databytesareinDIRECTformat.Asanexample,ifa
10mΩsenseresistorisusedinconjunctionwitha50V/V
current-senseamplifier,theIOUT_CAL_GAINshouldbe
setto500mΩor1388h.
USER NOTE:Thefull-scaleADCvoltageonthedevice
is 2.048V. The valueofthe sense resistorandcurrent-
sense amplifier gain must be scaled appropriately. Also,
the maximum voltage at the RSn inputs must be less
than4V.Themaximumoutputimpedanceofthecurrent-
senseamplifierislimitedbythesettingoftheADC_TIME
bits in MFR_MODE. See the Recommended Operating
Conditions section for details.
VOUT_OV_FAULT_LIMIT (40h)
The VOUT_OV_FAULT_LIMIT command sets the
value of the output voltage that causes an output
overvoltage fault. The monitored voltage must drop
by at least 2% below the limit before the fault is
allowed to clear. The 2 data bytes are in DIRECT
format. In response to the VOUT_OV_FAULT_LIMIT
beingexceeded,thedevicedoesthefollowing:
1) SetstheVOUT_OVbitandtheVOUTbitinSTATUS_
WORD.
2) SetstheVOUT_OV_FAULTbitinSTATUS_VOUT.
3) Responds as specified in the MFR_FAULT_
RESPONSE.
4) NotifiesthehostthroughALERT assertion (if enabled
inMFR_MODE).
VOUT_OV_WARN_LIMIT (42h)
The VOUT_OV_WARN_LIMIT commandsets the value
of the output voltage that causes an output-voltage high
warning. The monitored voltage must drop by at least 2%
below the limit before the warning is allowed to clear. This
value is typically less than the output overvoltage thresh-
oldinVOUT_OV_FAULT_LIMIT.The2databytesarein
DIRECTformat. InresponsetotheVOUT_OV_WARN_
LIMITbeingexceeded,thedevicedoesthefollowing:
1) SetstheVOUTbitinSTATUS_WORD.
2) SetstheVOUT_OV_WARNbitinSTATUS_VOUT.
3) NotifiesthehostusingALERT assertion (if enabled in
MFR_MODE).
VOUT_UV_WARN_LIMIT (43h)
The VOUT_UV_WARN_LIMIT command sets the value
of the output voltage that causes an output-voltage low
warning. The monitored voltage must increase by at least
2% above the limit before the warning is allowed to clear.
This value is typically greater than the output undervolt-
age-fault threshold in VOUT_UV_FAULT_LIMIT. This
warning is masked until the output voltage reaches the
programmedPOWER_GOOD_ONforthefirsttimeand
also during turn-off when the power supply is disabled. If
voltage is being monitored, this should be set to a value
greater than 100mV. The 2 data bytes are in DIRECT
format.InresponsetoviolationoftheVOUT_UV_WARN_
LIMIT,thedevicedoesthefollowing:
1) SetstheVOUTbitinSTATUS_WORD.
2) SetstheVOUT_UV_WARNbitinSTATUS_VOUT.
3) NotifiesthehostusingALERT assertion (if enabled in
MFR_MODE).
VOUT_UV_FAULT_LIMIT (44h)
The VOUT_UV_FAULT_LIMIT command sets the value
of the output voltage that causes an output undervoltage
fault. The monitored voltage must increase by at least
2% above the limit before the fault is allowed to clear.
This fault is masked until the output voltage reaches the
programmed POWER_GOOD_ON for the first time and
also during turn-off when the power supply is disabled. I f
voltage is being monitored, this should be set to a value
greater than 100mV.  The 2 data bytes are in DIRECT
format.InresponsetoviolationoftheVOUT_UV_FAULT_
LIMIT,thedevicedoesthefollowing:
1) SetstheVOUTbitinSTATUS_WORD.
2) SetstheVOUT_UV_FAULTbitinSTATUS_VOUT.
3) RespondsasspecifiedinMFR_FAULT_RESPONSE.
4) NotifiesthehostusingALERT assertion (if enabled in
MFR_MODE).
IOUT_OC_WARN_LIMIT (46h)
The IOUT_OC_WARN_LIMIT command sets the value
of the current that causes an overcurrent warning. The
monitored current must decrease by at least 5% below
the limit before the warning is allowed to clear. This
value is typically less than the overcurrent-fault thresh-
oldinIOUT_OC_FAULT_LIMIT.The2databytesarein
DIRECTformat.InresponsetoviolationoftheIOUT_OC_
WARN_LIMIT,thedevicedoesthefollowing:
1) SetstheIOUTbitinSTATUS_WORD.
2) SetstheIOUT_OC_WARNbitinSTATUS_IOUT.
3) NotifiesthehostusingALERT assertion (if enabled in
MFR_MODE).