Description

The LM75A is a temperature-to-digital converter using an on-chip band gap temperature

sensor and Sigma-delta A-to-D conversion technique. The device is also a thermal

detector providing an overtemperature detection output. The LM75A contains a number of data registers: Configuration register (Conf) to store the device settings such as device

operation mode, OS operation mode, OS polarity and OS fault queue as described in

Section 7 “Functional description”; temperature register (Temp) to store the digital temp

reading, and set-point registers (Tos and Thyst) to store programmable overtemperature

shutdown and hysteresis limits, that can be communicated by a controller via the 2-wire

serial I2C-bus interface. The device also includes an open-drain output (OS) which

becomes active when the temperature exceeds the programmed limits. There are three

selectable logic address pins so that eight devices can be connected on the same bus

without address conflict.

Features

■ Pin-for-pin replacement for industry standard LM75 and offers improved temperature resolution of 0.125 °C and specification of a single part over power supply range from 2.8 V to 5.5 V

■ Small 8-pin package types: SO8 and TSSOP8

■ I2C-bus interface with up to 8 devices on the same bus

■ Power supply range from 2.8 V to 5.5 V

■ Temperatures range from −55 °C to +125 °C

■ 11-bit ADC that offers a temperature resolution of 0.125 °C

■ Temperature accuracy of:

♦ ±2 °C from −25 °C to +100 °C

♦ ±3 °C from −55 °C to +125 °C

■ Programmable temperature threshold and hysteresis set points

■ Supply current of 3.5 µA in shutdown mode for power conservation

■ Stand-alone operation as thermostat at power-up

■ ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101

■ Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA

Applications

■ System thermal management

■ Personal computers

■ Electronics equipment

■ Industrial controllers