LM339 Family (3 parts in our catalog)

The LM339 is a quad independent precision voltage comparator family originally introduced by National Semiconductor and now produced by TI, STMicroelectronics, and ON Semiconductor. It is designed to operate from a single power supply over a wide range of voltages or from split supplies. These devices feature a common-mode input voltage range that includes ground, even when operated from a single supply, and utilize open-collector outputs to enable level shifting and wired-OR logic configurations in embedded systems.

Key Features

• Wide supply voltage range from 2V to 36V or +/-1V to +/-18V
• Low supply current drain of 0.8 mA independent of supply voltage
• Low input biasing current of 25 nA and offset current of 5 nA
• Open-collector outputs for flexible logic interfacing and level shifting
• Input common-mode voltage range includes ground level

Sub-families

Typical Use Cases

Embedded engineers primarily utilize the LM339 for basic signal threshold detection and windowing applications. Common use cases include battery level monitoring, where the comparator triggers a low-battery interrupt when voltage drops below a defined Zener reference. In power supply design, it serves as an over-voltage or under-voltage protector by driving a shutdown pin or relay. Its open-collector architecture makes it ideal for interfacing low-voltage microcontrollers with higher-voltage industrial sensors or for creating simple oscillator circuits. Additionally, the LM339 is frequently used in zero-crossing detectors for AC power control and PWM generation circuits where high-speed switching is not the primary constraint. Its ability to sink 16 mA allows it to drive small LEDs or optocouplers directly, simplifying the BOM in cost-sensitive industrial and consumer electronics.

Popular Variants

Top variants from across the family, with specs that differentiate them.

Alternatives to Consider