LM95231
www.ti.com
SNIS139E –FEBRUARY 2005–REVISED MARCH 2013
LM95231 Precision Dual Remote Diode Temperature Sensor with SMBus Interface and
TruTherm™ Technology
Check for Samples: LM95231
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FEATURES
KEY SPECIFICATIONS
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Accurately Senses Die Temperature of Remote
ICs or Diode Junctions
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Remote Temperature Accuracy ±0.75°C (max)
Local Temperature Accuracy ±3.0°C (max)
Supply Voltage 3.0V to 3.6V
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Uses TruTherm Technology for Precision
“Thermal Diode” Temperature Measurement
Supply Current 402μA (typ)
Thermal Diode Input Stage with Analog
Filtering
APPLICATIONS
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Thermal Diode Digital Filtering
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Processor/Computer System Thermal
Management
Intel Pentium 4 Processor on 90nm Process or
2N3904 Non-ideality Selection
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e.g. Laptop, Desktop, Workstations, Server)
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Remote Diode Fault Detection
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Electronic Test Equipment
Office Electronics
On-board Local Temperature Sensing
Remote Temperature Readings Without Digital
Filtering:
DESCRIPTION
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0.125°C LSb
The LM95231 is a precision dual remote diode
temperature sensor (RDTS) that uses Texas
Instruments' TruTherm technology. The 2-wire serial
interface of the LM95231 is compatible with SMBus
2.0. The LM95231 can sense three temperature
zones, it can measure the temperature of its own die
as well as two diode connected transistors. The
LM95231 includes digital filtering and an advanced
input stage that includes analog filtering and
TruTherm technology that reduces processor-to-
processor non-ideality spread. The diode connected
transistors can be a “thermal diode” as found in Intel
and AMD processors or can simply be a diode
10-bits Plus Sign or 11-bits Programmable
Resolution
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11-bits Resolves Temperatures Above
127 °C
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Remote Temperature Readings with Digital
Filtering:
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0.03125°C LSb with Filtering
12-bits Plus Sign or 13-bits Programmable
Resolution
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13-bits Resolves Temperatures Above
127°C
connected
MMBT3904
transistor.
TruTherm
technology allows accurate measurement of “thermal
diodes” found on small geometry processes, 90nm
and below. The LM95231 supports user selectable
thermal diode non-ideality of either a Pentium 4
processor on 90nm process or 2N3904.
Local Temperature Readings:
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0.25°C
9-bits Plus Sign
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Status Register Support
The LM95231 resolution format for remote
temperature readings can be programmed to be 11-
bits signed or unsigned with the digital filtering
disabled. When the filtering is enabled the resolution
increases to 13-bits signed or unsigned. In the
unsigned mode the LM95231 remote diode readings
can resolve temperatures above 127°C. Local
temperature readings have a resolution of 9-bits plus
sign.
Programmable Conversion Rate Allows User
Optimization of Power Consumption
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Shutdown Mode One-shot Conversion Control
SMBus 2.0 Compatible Interface, Supports
TIMEOUT
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8-pin VSSOP Package
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005–2013, Texas Instruments Incorporated