LM75A Datasheet – Temperature Sensor and Thermal Watchdog

Part Number: LM75A

Function: Digital temperature sensor and thermal Watchdog

Package: SOIC, VSSOP 8 Pin Type

Manufacturer: NXP Semiconductors.


LM75A datasheet



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.


1. Programmable temperature threshold and hysteresis set points
2. I2C-bus interface with up to 8 devices on the same bus
3. Power supply range from 2.8 V to 5.5 V
4. Temperatures range from−55°C to +125°C
5. 11-bit ADC that offers a temperature resolution of 0.125°C
6. Supply current of 3.5µA in shutdown mode for power conservation
7. Stand-alone operation as thermostat at power-up
8. Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA


1. System thermal management

2. Personal computers

3. Electronics equipment

4. Industrial controllers


Other data sheets are available within the file: LM75AD, LM75ADP

LM75A Datasheet PDF Download

LM75A pdf