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LM35 Precision Centigrade Temperature Sensors

November 2000

LM35 Precision Centigrade Temperature Sensors
General Description
The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in ˚ Kelvin, as the user is notrequired to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of ± 1⁄4˚C at room temperature and ± 3⁄4˚C over a full −55 to +150˚C temperature range. Low cost is assured by trimming and calibration at the wafer level. The LM35’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 60 µA from its supply, it has very low self-heating, less than 0.1˚C in still air. The LM35 is rated to operate over a −55˚ to +150˚C temperature range, while the LM35C is rated for a −40˚ to +110˚C range (−10˚with improved accuracy). The LM35 series is available packaged in hermetic TO-46 transistor packages, while the LM35C, LM35CA, and LM35D are also available in the plastic TO-92 transistor package. The LM35D is also available in an 8-lead surface mount small outline package and a plastic TO-220 package.

Features
n n n n n n n n n n n Calibrated directly in ˚ Celsius (Centigrade) Linear + 10.0mV/˚C scale factor 0.5˚C accuracy guaranteeable (at +25˚C) Rated for full −55˚ to +150˚C range Suitable for remote applications Low cost due to wafer-level trimming Operates from 4 to 30 volts Less than 60 µA current drain Low self-heating, 0.08˚C in still air Nonlinearity only ± 1⁄4˚C typical Low impedance output, 0.1 Ω for 1 mA load

Typical Applications

DS005516-4 DS005516-3

FIGURE 1.Basic Centigrade Temperature Sensor (+2˚C to +150˚C)

Choose R1 = −VS/50 µA V OUT =+1,500 mV at +150˚C = +250 mV at +25˚C = −550 mV at −55˚C

FIGURE 2. Full-Range Centigrade Temperature Sensor

© 2000 National Semiconductor Corporation

DS005516

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LM35

Connection Diagrams
TO-46 Metal Can Package* SO-8 Small Outline Molded Package

DS005516-1

DS005516-21*Case is connected to negative pin (GND)

N.C. = No Connection

Order Number LM35H, LM35AH, LM35CH, LM35CAH or LM35DH See NS Package Number H03H TO-92 Plastic Package

Top View Order Number LM35DM See NS Package Number M08A TO-220 Plastic Package*

DS005516-2

Order Number LM35CZ, LM35CAZ or LM35DZ See NS Package Number Z03A

DS005516-24

*Tab is connected to the negative pin (GND).Note: The LM35DT pinout is different than the discontinued LM35DP.

Order Number LM35DT See NS Package Number TA03F

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2

LM35

Absolute Maximum Ratings (Note 10)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage Output Voltage Output Current StorageTemp.; TO-46 Package, TO-92 Package, SO-8 Package, TO-220 Package, Lead Temp.: TO-46 Package, (Soldering, 10 seconds) +35V to −0.2V +6V to −1.0V 10 mA −60˚C −60˚C −65˚C −65˚C to to to to +180˚C +150˚C +150˚C +150˚C

TO-92 and TO-220 Package, (Soldering, 10 seconds) 260˚C SO Package (Note 12) Vapor Phase (60 seconds) 215˚C Infrared (15 seconds) 220˚C ESD Susceptibility (Note 11) 2500V SpecifiedOperating Temperature Range: TMIN to T MAX (Note 2) LM35, LM35A −55˚C to +150˚C LM35C, LM35CA −40˚C to +110˚C LM35D 0˚C to +100˚C

300˚C

Electrical Characteristics
(Notes 1, 6) LM35A Parameter Conditions Typical Accuracy (Note 7) T A =+25˚C T A =−10˚C T A =TMAX T A =TMIN Nonlinearity (Note 8) Sensor Gain (Average Slope) Load Regulation (Note 3) 0≤IL≤1 mA Line Regulation (Note 3) Quiescent...
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