LM74

General Description

The LM74 is a temperature sensor, Delta-Sigma analog-to-

digital converter with an SPI and MICROWIRE compatible

interface. The host can query the LM74 at any time to read

temperature. A shutdown mode decreases power consump-

tion to less than 10 µA. This mode is useful in systems where

low average power consumption is critical.

The LM74 has 12-bit plus sign temperature resolution

(0.0625˚C per LSB) while operating over a temperature

range of −55˚C to +150˚C.

The LM74’s 3.0V to 5.5V supply voltage range, low supply

current and simple SPI interface make it ideal for a wide

range of applications. These include thermal management

and protection applications in hard disk drives, printers, elec-

tronic test equipment, and office electronics. The LM74 is

available in the SO-8 package as well as an 5-Bump micro

SMD package.

Applications

n

System Thermal Management

n

Personal Computers

n

Disk Drives

n

Office Electronics

n

Electronic Test Equipment

Features

n

0.0625˚C temperature resolution.

n

Shutdown mode conserves power between temperature

reading

n

SPI and MICROWIRE Bus interface

n

5-Bump micro SMD package saves space

Key Specifications

3.0V or 2.65V to

5.5V

operating

265µA (typ)

520µA (max)

shutdown

3µA (typ)

Accuracy

−10˚C to 65˚C

−25˚C to 110˚C

−55˚C to 125˚C

Simplified Block Diagram

10090901

April 2003

© 2003 National Semiconductor Corporation

DS100909

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