Hysteresis circuit.

摘要

A differential pair of first and second transistors (Q10, Q11) for voltage comparison is provided, and a bias circuit (R12, R13) for setting a reference voltage is connected to the base of the second transistor. A differential pair of third and fourth transistors (Q12, Q13) is provided for reference voltage switching. The third and fourth transistors have their bases connected to the collectors of the first and second transistors and their collectors connected to the bias circuit in a positive feedback relation with respect to the base of the first transistor.