LM70

Sensor

General Description

The

LM70

is

a

temperature

sensor,

Delta-Sigma

analog-to-digital converter with an SPI and MICROWIRE

compatible interface available in LLP and MSOP 8-pin pack-

ages. The host can query the LM70 at any time to read tem-

perature. A shutdown mode decreases power consumption

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

average power consumption is critical.

The LM70 has 10-bit plus sign temperature resolution

(0.25˚C per LSB) while operating over a temperature range

of −55˚C to +150˚C.

The LM70’s 2.65V 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.

Applications

n

System Thermal Management

n

Personal Computers

n

Disk Drives

n

Office Electronics

n

Electronic Test Equipment

Features

n

0.25˚C temperature resolution.

n

Shutdown mode conserves power between temperature

reading

n

SPI and MICROWIRE Bus interface

n

MSOP-8 and LLP-8 packages save space

Key Specifications

2.65V to 5.5V

operating

260µA (typ)

490µA (max)

shutdown

12µA (typ)

Accuracy

−40˚C to 85˚C

−10˚C to 65˚C

+1.5/−2˚C(max)

−55˚C to 125˚C

+3/−2˚C(max)

−55˚C to 150˚C

+3.5/−2˚C(max)

Simplified Block Diagram

DS101223-1

July 2000

© 2000 National Semiconductor Corporation

DS101223

www.national.com