LM50

SOT-23 Single-Supply Centigrade Temperature Sensor

General Description

The LM50 is a precision integrated-circuit temperature sen-

sor that can sense a −40˚C to +125˚C temperature range us-

ing a single positive supply. The LM50’s output voltage is lin-

early proportional to Celsius (Centigrade) temperature

(+10 mV/˚C) and has a DC offset of +500 mV. The offset al-

lows reading negative temperatures without the need for a

negative supply. The ideal output voltage of the LM50 ranges

from +100 mV to +1.75V for a −40˚C to +125˚C temperature

range. The LM50 does not require any external calibration or

Trimming and calibration of the LM50 at the wafer level as-

sure low cost and high accuracy. The LM50’s linear output,

+500 mV offset, and factory calibration simplify circuitry re-

quired in a single supply environment where reading nega-

tive temperatures is required. Because the LM50’s quiescent

current is less than 130 µA, self-heating is limited to a very

low 0.2˚C in still air.

Applications

n Computers

n Disk Drives

n Battery Management

n Automotive

n FAX Machines

n Printers

n Portable Medical Instruments

n HVAC

n Power Supply Modules

Features

n Calibrated directly in degree Celsius (Centigrade)

n Linear + 10.0 mV/˚C scale factor

n Specified for full −40˚ to +125˚C range

n Suitable for remote applications

n Low cost due to wafer-level trimming

n Operates from 4.5V to 10V

n Less than 130 µA current drain

n Low self-heating, less than 0.2˚C in still air

n Nonlinearity less than 0.8˚C over temp

Connection Diagram

Order

SOT-23

Supplied As

Number

Device Marking

LM50BIM3

T5B

1000 Units on Tape

and Reel

LM50CIM3

T5C

1000 Units on Tape

and Reel

LM50BIM3X

T5B

3000 Units on Tape

and Reel

LM50CIM3X

T5C

3000 Units on Tape

and Reel

Typical Application

SOT-23

DS012030-1

Top View

See NS Package Number MA03B

DS012030-3

FIGURE 1. Full-Range Centigrade Temperature Sensor (−40˚C to +125˚C)

July 1999

© 1999 National Semiconductor Corporation

DS012030

www.national.com