The LM75 temperature sensor includes a delta-sigma analog-to-digital converter, and a digital overtemperature detector. The host can query the LM75 through its I2C interface to read temperature at any time. The open-drain overtemperature output (OS) sinks current when the programmable temperature limit is exceeded. The OS output operates in either of two modes, comparator or interrupt. The host controls the temperature at which the alarm is asserted (TOS) and the hysteresis temperature below which the alarm condition is not valid (THYST). Also, the LM75’s TOS and THYST registers can be read by the host. The address of the LM75 is set with three pins to allow multiple devices to work on the same bus. Power-up is in comparator mode, with defaults of TOS = +80°C and THYST = +75°C. The 3.0V to 5.5V supply voltage range, low supply current, and I2C interface make the LM75 ideal for many applications in thermal management and protection.
The LM75 is a digital temperature sensor and thermal watchdog that uses a delta‑sigma ADC and an I²C‑compatible 2‑wire interface. It provides an open‑drain overtemperature output that can operate in comparator or interrupt mode, with programmable alarm thresholds (Tos and THYST) and low power consumption across a 3.0 V to 5.5 V supply range.
This manual includes the device’s absolute maximum ratings, electrical characteristics, pin descriptions, timing diagrams, register maps, and typical operating curves. It also provides ordering information, package outlines, and application notes for thermal management and protection in computers, test equipment, and other electronics.
| Supply Voltage Range | 3.0 V to 5.5 V |
|---|---|
| Low Operating Supply Current | 250 pA typ, 1 mA max |
| Resolution | 9 bits |
| Operating Temperature Range | -55 °C to +125 °C |
| Maximum Devices per I²C Bus | 8 |
Up to eight LM75 devices can be connected to a single I²C bus.
The sensor provides a 9‑bit temperature resolution.
The LM75 operates from 3.0 V to 5.5 V supply voltage.