LM80

LM80 is a temperature-sensor integrated circuit series introduced by National Semiconductor (now part of Texas Instruments). It provides a direct, analog measurement of ambient temperature. The output is a voltage that is linearly proportional to temperature, allowing simple conversion using an ADC and a reference.

The device operates from a single supply, typically in the 4.5 to 5.5 V range, and is specified for a broad operating temperature range, commonly about -40°C to +125°C. The output slope is on the order of tens of millivolts per degree Celsius, enabling resolution of 0.5°C to 1°C with standard analog-to-digital conversion.

LM80 devices are available in small packages such as TO-92 and surface-mount variants, making them suitable for desktop and embedded electronics, including power supplies, motherboards, and other equipment requiring local temperature monitoring.

The LM80 family consists of several versions with similar sensing characteristics but different packaging, calibration data, and temperature ranges. It is generally used when a simple, cost-effective analog temperature sensor is adequate, avoiding the need for digital communication interfaces.

History and availability: The LM80 was introduced in the 1980s and remained widely used through the 1990s and early 2000s. Following corporate acquisitions, newer temperature sensors with digital interfaces and higher accuracy have largely supplanted LM80 in new designs, but LM80 devices may still appear in legacy equipment and in some niche applications.

See also: LM75, temperature sensor, National Semiconductor.