LM70

SPI/MICROWIRE 10-Bit plus Sign Digital Temperature

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 packages. The

host can query the LM70 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.

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

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Electronic Test Equipment

Features

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0.25˚C temperature resolution.

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Shutdown mode conserves power between temperature

reading

n

SPI and MICROWIRE Bus interface

n

MSOP-8 and LLP-8 packages save space

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UL Recognized Component

Key Specifications

2.65V to 5.5V

operating

260 µA (typ)

490 µA (max)

shutdown

12 µA (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

10122301

February 2006

© 2006 National Semiconductor Corporation

DS101223

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