LM95231EVAL National Semiconductor, LM95231EVAL Datasheet

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LM95231EVAL

Manufacturer Part Number
LM95231EVAL
Description
BOARD EVALUATION LM95231
Manufacturer
National Semiconductor
Series
TruTherm®r
Datasheets

Specifications of LM95231EVAL

Sensor Type
Temperature
Sensing Range
0°C ~ 125°C
Interface
SMBus (2-Wire/I²C)
Sensitivity
±1°C
Voltage - Supply
3 V ~ 3.6 V
Embedded
Yes, MCU, 8-Bit
Utilized Ic / Part
LM95231
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
© 2006 National Semiconductor Corporation
LM95231
Precision Dual Remote Diode Temperature Sensor with
SMBus Interface and TruTherm
General Description
The LM95231 is a precision dual remote diode temperature
sensor (RDTS) that uses National’s 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 con-
nected transistors can be a “thermal diode” as found in Intel
and AMD processors or can simply be a diode 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
processor on 90nm process or 2N3904.
The LM95231 resolution format for remote temperature
readings can be programmed to be 11-bits signed or un-
signed with the digital filtering disabled. When the filtering is
enabled the resolution increases to 13-bits signed or un-
signed. In the unsigned mode the LM95231 remote diode
readings can resolve temperatures above 127˚C. Local tem-
perature readings have a resolution of 9-bits plus sign.
Features
n Accurately senses die temperature of remote ICs or
n Uses TruTherm technology for precision “thermal diode”
n Thermal diode input stage with analog filtering
n Thermal diode digital filtering
n Intel Pentium 4 processor on 90nm process or 2N3904
Connection Diagram
TruTherm
I2C
Pentium
diode junctions
temperature measurement
non-ideality selection
®
is a registered trademark of Philips Corporation.
®
is a registered trademark of Intel Corporation.
is a trademark of National Semiconductor Corporation.
DS201202
TOP VIEW
®
MSOP-8
4
n Remote diode fault detection
n On-board local temperature sensing
n Remote temperature readings without digital filtering:
n Remote temperature readings with digital filtering:
n Local temperature readings:
n Status register support
n Programmable conversion rate allows user optimization
n Shutdown mode one-shot conversion control
n SMBus 2.0 compatible interface, supports TIMEOUT
n 8-pin MSOP package
Key Specifications
Applications
n Processor/Computer System Thermal Management
n Electronic Test Equipment
n Office Electronics
j
j
j
j
of power consumption
— 0.125 ˚C LSb
— 10-bits plus sign or 11-bits programmable resolution
— 11-bits resolves temperatures above 127 ˚C
— 0.03125 ˚C LSb with filtering
— 12-bits plus sign or 13-bits programmable resolution
— 13-bits resolves temperatures above 127 ˚C
— 0.25 ˚C
— 9-bits plus sign
Remote Temperature Accuracy
Local Temperature Accuracy
Supply Voltage
Supply Current
(e.g. Laptop, Desktop, Workstations, Server)
Technology
20120202
±
±
0.75˚C (max)
www.national.com
3.0V to 3.6V
August 2006
3.0˚C (max)
402µA (typ)

Related parts for LM95231EVAL

LM95231EVAL Summary of contents

Page 1

... Thermal diode input stage with analog filtering n Thermal diode digital filtering n Intel Pentium 4 processor on 90nm process or 2N3904 non-ideality selection Connection Diagram TruTherm ™ trademark of National Semiconductor Corporation. I2C ® registered trademark of Philips Corporation. Pentium ® registered trademark of Intel Corporation. © 2006 National Semiconductor Corporation Technology ™ ...

Page 2

Ordering Information Package Part Number Marking LM95231BIMM T23B MUA08A (MSOP-8) LM95231BIMMX T23B MUA08A (MSOP-8) LM95231BIMM-1 T25B MUA08A (MSOP-8) LM95231BIMMX-1 T25B MUA08A (MSOP-8) LM95231BIMM-2 T26B MUA08A (MSOP-8) LM95231BIMMX-2 T26B MUA08A (MSOP-8) LM95231CIMM T23C MUA08A (MSOP-8) LM95231CIMMX T23C MUA08A (MSOP-8) LM95231CIMM-1 T25C ...

Page 3

Pin Descriptions (Continued) Label Pin # D1− 2 D2+ 3 D2− 4 GND SMBDAT 7 SMBCLK 8 Simplified Block Diagram Function Diode Return Current Sink To Diode Cathode. A capacitor is not required between D1+ and ...

Page 4

Absolute Maximum Ratings Supply Voltage Voltage at SMBDAT, SMBCLK Voltage at Other Pins Input Current at All Pins (Note 2) Package Input Current (Note 2) SMBDAT Output Sink Current Junction Tempeature (Note 3) Storage Temperature ESD Susceptibility (Note 4) Human ...

Page 5

Temperature-to-Digital Converter Characteristics Unless otherwise noted, these specifications apply for V ≤T ≤ all other limits MIN A MAX A junction temperature of the remote thermal diode. Parameter Diode Source Current Power-On Reset Threshold Logic ...

Page 6

Logic Electrical Characteristics SMBus Digital Switching Characteristics Unless otherwise noted, these specifications apply for V pF. Boldface limits apply for characteristics of the LM95231 fully meet or exceed the published specifications of the SMBus version 2.0. ...

Page 7

Logic Electrical Characteristics Pin Label Circuit # 1 D1 D1− D2 D2− GND SMBDAT C 8 SMBCLK C Note 3: Thermal resistance junction-to-ambient when attached to ...

Page 8

Typical Performance Characteristics Thermal Diode Capacitor or PCB Leakage Current Effect Remote Diode Temperature Reading Conversion Rate Effect on Average Power Supply Current 1.0 Functional Description The LM95231 is a digital sensor that can sense the tempera- ture of 3 ...

Page 9

Functional Description the remote diodes to sense temperatures above 127˚C. Local temperature resolution is not programmable and is always 9-bits plus sign and has a 0.25˚C LSb. The LM95231 remote diode temperature accuracy will be trimmed for the thermal ...

Page 10

Functional Description 1.4 TEMPERATURE DATA FORMAT Temperature data can only be read from the Local and Remote Temperature registers . Remote temperature data with the digital filter off is repre- sented by an 11-bit, two’s complement word or unsigned ...

Page 11

Functional Description 1.7 COMMUNICATING with the LM95231 The data registers in the LM95231 are selected by the Command Register. At power-up the Command Register is set to “00”, the location for the Read Local Temperature Register. The Command Register ...

Page 12

Functional Description (a) Serial Bus Write to the Internal Command Register (b) Serial Bus Write to the internal Command Register followed by a Data Byte (c) Serial Bus byte Read from a Register with the internal Command Register preset ...

Page 13

Functional Description 1.8 SERIAL INTERFACE RESET In the event that the SMBus Master is RESET while the LM95231 is transmitting on the SMBDAT line, the LM95231 must be returned to a known state in the communication protocol. This may ...

Page 14

LM95231 Registers 2.1 STATUS REGISTER (Read Only Address 02h Busy 0 Bits Name 7 Busy 6-4 Reserved 3 Remote 2 TruTherm Mode Enabled (R2TME) 2 Remote 1 TruTherm Mode Enabled (R2TME) 1 Remote Diode 2 Missing (RD2M) ...

Page 15

LM95231 Registers 2.3 REMOTE DIODE FILTER CONTROL REGISTER (Read/write Address 06h Bits Name 7-3 Reserved 2 Remote 2 Filter Enable (R2FE) 1 Reserved 0 Remote 1 Filter Enable (R1FE) Power up default is 05h. ...

Page 16

LM95231 Registers Bits Description 2-0 R1M2:R1M0 Power up default is 01h. 2.6 LOCAL and REMOTE MSB and LSB TEMPERATURE REGISTERS (Read Only Address 10h) 9-bit plus sign format: BIT Value Temperature Data: LSb = 1˚C. (Read Only Address 20h) ...

Page 17

LM95231 Registers 2.7 MANUFACTURERS ID REGISTER (Read Address FEh) The default value is 01h. 2.8 DIE REVISION CODE REGISTER (Read Address FFh) The default value is A1h. This register will increment by 1 every time there is a revision ...

Page 18

... Compensating for Different Non-Ideality In order to compensate for the errors introduced by non- ideality, the temperature sensor is calibrated for a particular processor. National Semiconductor temperature sensors are always calibrated to the typical non-ideality and series resis- tance of a given processor type. The LM95231 is calibrated ...

Page 19

Applications Hints supporting the MMBT3904 transistor and the Pentium 4 processor on 90nm process without the requirement for additional trims. For most accurate measurements TruTherm mode should be turned on when measuring the Pentium 4 processor on the 90nm ...

Page 20

... BANNED SUBSTANCE COMPLIANCE National Semiconductor follows the provisions of the Product Stewardship Guide for Customers (CSP-9-111C2) and Banned Substances and Materials of Interest Specification (CSP-9-111S2) for regulatory environmental compliance. Details may be found at: www.national.com/quality/green. ...

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