LM397

The LM397 from Texas Instruments is a versatile single voltage comparator featuring an input common-mode range that includes ground. It is designed to operate efficiently from single 5-V to 30-V power supplies or split power supplies, with a low supply current that remains nearly constant regardless of the supply voltage magnitude.

This comparator boasts a fast response time of 440 ns with a 50-mV overdrive, making it suitable for applications requiring quick signal detection. Key electrical characteristics include a low input bias current of 7 nA, a low input offset current of ±1 nA, and a low input offset voltage of ±2 mV. The device operates within an industrial temperature range of -40°C to +85°C.

The LM397 features an open-collector output stage, allowing for flexible interfacing with TTL, CMOS, and other logic levels through an external pull-up resistor. This level-translating capability enhances its utility in various digital systems. It is available in the space-saving 5-Pin SOT-23 package, measuring 2.90 mm x 1.60 mm, and is pin-compatible with TI's TL331 comparator.

Applications for the LM397 include A/D converters, pulse and square-wave generators, peak detectors, and general industrial applications where reliable voltage comparison is needed.