LM34

Precision Fahrenheit Temperature Sensors

General Description

The LM34 series are precision integrated-circuit temperature

sensors, whose output voltage is linearly proportional to the

Fahrenheit temperature. The LM34 thus has an advantage

over linear temperature sensors calibrated in degrees

Kelvin, as the user is not required to subtract a large con-

stant voltage from its output to obtain convenient Fahrenheit

scaling. The LM34 does not require any external calibration

ture range. Low cost is assured by trimming and calibration

at the wafer level. The LM34’s low output impedance, linear

output, and precise inherent calibration make interfacing to

readout or control circuitry especially easy. It can be used

with single power supplies or with plus and minus supplies.

As it draws only 75 µA from its supply, it has very low

self-heating, less than 0.2˚F in still air. The LM34 is rated to

operate over a −50˚ to +300˚F temperature range, while the

LM34C is rated for a −40˚ to +230˚F range (0˚F with im-

proved accuracy). The LM34 series is available packaged in

hermetic TO-46 transistor packages, while the LM34C,

LM34CA and LM34D are also available in the plastic TO-92

transistor package. The LM34D is also available in an 8-lead

surface mount small outline package. The LM34 is a comple-

ment to the LM35 (Centigrade) temperature sensor.

Features

n Calibrated directly in degrees Fahrenheit

n Linear +10.0 mV/˚F scale factor

n 1.0˚F accuracy guaranteed (at +77˚F)

n Rated for full −50˚ to +300˚F range

n Suitable for remote applications

n Low cost due to wafer-level trimming

n Operates from 5 to 30 volts

n Less than 90 µA current drain

n Low self-heating, 0.18˚F in still air

n Low-impedance output, 0.4

Ω for 1 mA load

Connection Diagrams

Note 1: Case is connected to negative pin (GND).

TO-46

Metal Can Package

(Note 1)

DS006685-1

Order Numbers LM34H,

LM34AH, LM34CH,

LM34CAH or LM34DH

See NS Package

Number H03H

TO-92

Plastic Package

DS006685-2

Order Number LM34CZ,

LM34CAZ or LM34DZ

See NS Package

Number Z03A

SO-8

Small Outline

Molded Package

DS006685-20

N.C. = No Connection

Top View

Order Number LM34DM

See NS Package Number M08A

July 1999

© 1999 National Semiconductor Corporation

DS006685

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