LM20

2.4V, 10µA, SC70, micro SMD Temperature Sensor

General Description

The LM20 is a precision analog output CMOS integrated-

circuit temperature sensor that operates over a −55˚C to

+130˚C temperature range. The power supply operating

range is +2.4 V to +5.5 V. The transfer function of LM20 is

predominately linear, yet has a slight predictable parabolic

curvature. The accuracy of the LM20 when specified to a

ture of +30˚C. The temperature error increases linearly and

extremes. The temperature range is affected by the power

supply voltage. At a power supply voltage of 2.7 V to 5.5 V

the temperature range extremes are +130˚C and −55˚C.

Decreasing the power supply voltage to 2.4 V changes the

negative extreme to −30˚C, while the positive remains at

+130˚C.

The LM20’s quiescent current is less than 10 µA. Therefore,

self-heating is less than 0.02˚C in still air. Shutdown capa-

bility for the LM20 is intrinsic because its inherent low power

consumption allows it to be powered directly from the output

of many logic gates or does not necessitate shutdown at all.

Applications

n

Cellular Phones

n

Computers

n

Power Supply Modules

n

Battery Management

n

FAX Machines

n

Printers

n

HVAC

n

Disk Drives

n

Appliances

Features

n

Rated for full −55˚C to +130˚C range

n

Available in an SC70 and 2 micro SMD packages

n

Predictable curvature error

n

Suitable for remote applications

Key Specifications

+2.4V to +5.5V

10 µA (max)

160

Ω (max)

−2.5 mV (max)

Typical Application

Full-Range Celsius (Centigrade) Temperature Sensor (−55˚C to +130˚C)

Operating from a Single Li-Ion Battery Cell

Output Voltage vs Temperature

10090802

V

where:

10090824

October 2005

© 2005 National Semiconductor Corporation

DS100908

www.national.com