Datasheet

MAX34451 PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
www.maximintegrated.com
Maxim Integrated │ 65
Table 41. DS75LV Address Pin
Configuration
Table 42. MFR_TEMP_SENSOR_CONFIG
(F0h)
Applications Information
V
DD
, V
DDA
, and REG18 Decoupling
To achieve the best results when using the device,
decouple V
DD
 and V
DDA
power inputs each with a
0.1µFcapacitor.Ifpossible,useahigh-quality,ceramic,
surface-mount capacitor. Surface-mount components
minimize lead inductance, which improves performance,
and ceramic capacitors tend to have adequate high-
frequency response for decoupling applications. Decouple
the REG18 regulator output using 1µF and 10nF
capacitorswithamaximumESRof500mΩ.
Open-Drain Pins
MSDA, MSCL, SCL, SDA, FAULTn, SEQ, and ALERT
are open-drain pins and require external pullup resistors
connectedtoV
DD
to realize high logic levels.
PSEN0–PSEN11canbeuser-configuredaseitherCMOS
push-pull or open-drain outputs. When configured as
open drain (see MFR_PSEN_CONFIG), external pullup
resistorsconnected to V
DD
are required to realize high
logic levels.
Keep-Alive Circuit
In systems where the power to the device may not always
bepresent,akeep-alivecircuitconsisting ofaSchottky
diode and a bulk capacitor can be added to allow the
device time to orderly shut down the power supplies it is
controlling before power is lost.
Conguration Port
Some applications require the ability to configure the
devicewhenthedevicehasbeenmountedonaPCB.In
such applications, a 3- or 4-wire header can be added to
allow access to the slave I
2
Cpins.
Resistor-Dividers and Source
Impedance for RSn Inputs
The maximum full-scale voltage on the ADC inputs is
2.048V (nominal). A resistor-divider must be used to
measure voltages greater than 1.8V. The maximum
sourceimpedancetotheRSninputsisdeterminedbythe
ADC_TIMEbitsinMFR_MODE.SeetheRecommended
Operating Conditions section for more details.
Protecting Input Pins
InapplicationswherevoltagescanbeappliedtotheRSn
orCONTROLnsignals,whenV
DD
orV
DDA
is grounded,
a series 100Ω resistor is recommended to protect the
device by limiting power dissipation.
Exposed Pad Grounding
ThedeviceusestheexposedpadoftheTQFNpackage
asthecommonground(V
SS
)fortheentiredevice.The
exposed pad must be connected to the local ground plane.
PAGE
MAX34451 TEMP
SENSOR
DS75LV ADDRESS PIN
CONFIGURATION
A2 A1 A0
16 MAX34451 internal — — —
17
DS75LV(address90h) 0 0 0
18
DS75LV(address92h) 0 0 1
19
DS75LV(address94h) 0 1 0
20
DS75LV(address96h) 0 1 1
BIT NAME MEANING
15 ENABLE
0=Temperaturesensordisabled
1 = Temperature sensor enabled
14:0 0
Thesebitsalwaysreturna0.