Comparator circuit with precision hysteresis and high input impedance

摘要

The amplitude of the hysteresis of the circuit is determined principally by the intensity of the current produced by a generator by means of a "band gap" reference voltage, an internal resistance of the circuit, and the resistances connected to the emitters of the input-stage transistors, enabling a high degree of precision to be achieved. The inputs of the circuit are defined by the bases of the input-stage transistors and therefore have high impedance. The preferred application is for forming interface circuits for sensors to be fitted in motor vehicles.