LM75AD,112

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.
The LM75A can be configured for different operation conditions. It can be set in normal
mode to periodically monitor the ambient temperature, or in shutdown mode to minimize
power consumption. The OS output operates in either of two selectable modes:
OS comparator mode or OS interrupt mode. Its active state can be selected as either
HIGH or LOW. The fault queue that defines the number of consecutive faults in order to
activate the OS output is programmable as well as the set-point limits.

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