LM74A

(LM74 in Die Form)

General Description

The LM74A is a temperature sensor, Delta-Sigma analog-to-

digital converter with an SPI and MICROWIRE compatible

interface in die form. The host can query the LM74A at any

time to read temperature. A shutdown mode decreases

power consumption to less than 10 µA. This mode is useful

in systems where low average power consumption is critical.

This particular data sheet applies to the LM74 in die form.

The LM74 is available in the SO-8 package as well as an

5-Bump micro SMD package please refer to LM74 data

sheet for detailed specifictions pertaining to the packaged

parts.

The LM74A has 12-bit plus sign temperature resolution

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

range of −40˚C to +150˚C. The LM74A-5 MDA accuracy of

+150˚C.

The LM74A’s 4.5V to 5.5V or 3.0V to 3.6V 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, electronic test equipment, and office electronics.

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

LM74 is also available in a 5-Bump micro SMD and

8-pin MSOP

Key Specifications

LM74A-5

4.5V to 5.5V

LM74A-3

3.0V to 3.6V

operating

310µA (typ)

520µA (max)

shutdown

8µA (typ)

Temperature

Accuracy

0˚C to 140˚C

140˚C to 150˚C

Simplified Block Diagram

20017701

November 2004

© 2004 National Semiconductor Corporation

DS200177

www.national.com