LMx39/2901 Comparators Family (14 parts in our catalog)

The LMx39 and LM2901 family consists of four independent precision voltage comparators designed to operate from a single power supply over a wide range of voltages. Originally developed by Texas Instruments and now produced by multiple manufacturers like ONsemi and STMicroelectronics, these industry-standard devices feature a common-mode input voltage range that includes ground. Their open-collector outputs allow for easy level shifting and wired-OR logic configurations in diverse analog-to-digital interface circuits.

Key Features

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

Sub-families

Typical Use Cases

In embedded systems, the LM339 and LM2901 are primarily utilized for threshold detection and signal conditioning. Engineers frequently implement them as zero-crossing detectors to synchronize AC power control or as window comparators to monitor battery voltage levels and trigger protection circuits. Due to their open-collector architecture, they are ideal for interfacing 5V or 12V analog sensors with 3.3V microcontroller GPIOs without complex level-shifting hardware. They also serve effectively in oscillator circuits and pulse-width modulation (PWM) generators. The LM2901 variant is specifically qualified for automotive environments, where it handles high-temperature duty in engine control units and body electronics. Their robust design makes them a staple for industrial limit switching and basic logic-level translation in mixed-signal environments where high-speed switching is not the primary constraint.

Popular Variants

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

Alternatives to Consider