7

6

5

A0

A1

A2

Temperature

Threshold

Silicon Bandgap

Temperature

Sensor

Ð

1-Bit

D/A

10-Bit

Digital

Decimation

Filter

9-Bit Sigma-Delta ADC

Configuration

Register

Register

Pointer

Register

Point Register

Set Point

Comparator

3

O.S.

Reset

1

2

SDA

SCL

Two-Wire Interface

4

8

GND

LM75B, LM75C

SNIS153D – JULY 2009 – REVISED OCTOBER 2015

www.ti.com

7 Detailed Description

7.1 Overview

The LM75 temperature sensor incorporates a band-gap type temperature sensor and 9-bit ADC (Sigma-Delta

a conversion is in progress, it will be stopped and restarted after the read. A digital comparator is also

incorporated that compares a series of readings, the number of which is user-selectable, to user-programmable

setpoint and hysteresis values. The comparator trips the O.S. output line, which is programmable for mode and

polarity.

The LM75B contains all the functionality of the LM75C, plus two additional features:

•

The LM75B has an integrated low-pass filter on both the SDA and the SCL line. These filters increase

communications reliability in noisy environments.

•

2C

Digital Switching Characteristics) the LM75B will reset to the IDLE state (SDA set to high impedance) and

wait for a new start condition. The TIMEOUT feature is not functional in Shutdown Mode.

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Digital Temperature Sensor

The LM75 is an industry-standard digital temperature sensor with an integrated Sigma-Delta analog-to-digital

–25°C to 100°C and ±3°C over –55°C to 125°C.

The LM75 operates with a single supply from 2.7 V to 5.5 V. Communication is accomplished over a 2-wire

interface which operates up to 400kHz. The LM75 has three address pins, allowing up to eight LM75 devices to

operate on the same 2-wire bus. The LM75 has a dedicated over-temperature output (O.S.) with programmable

limit and hysteresis. This output has programmable fault tolerance, which allows the user to define the number of

consecutive error conditions that must occur before O.S. is activated.

12

Submit Documentation Feedback

Copyright © 2009–2015, Texas Instruments Incorporated

Product Folder Links: LM75B LM75C