The LM339ADT is a single comparator integrated circuit (IC) part manufactured by STMicroelectronics. It has several features that support its many applications, including an output signal that is compatible with TTL, a low input offset voltage, open-collector outputs, high output current, and operation from a single power supply. The LM339ADT is useful for applications that require a magnified voltage difference between two isolated points. It is commonly used for zero-cross detection and level-shifting in motor control applications. It is also used for systems that require fast, low-power comparator devices with high precision such as industrial motor control and amplifiers.