Hysteresis circuit with small hysteresis amplitude and oscillator using the hysteresis circuit

摘要

A hysteresis circuit producing a relatively stable hysteresis output signal, which includes a power source, a reference potential source, a transistor, a constant current source, output means and means for detecting the collector current and for controlling the constant current source. The transistor is connected at its collector to the power source via the constant current source and at its emitter to the reference potential source. The constant current source supplies a constant current switchable between first and second levels. The output means is responsive to the first and second levels of current for deriving a bilevel hysteresis output signal dependent on the first and second levels of current. The detecting and controlling means detects the collector current of the transistor and controls the current source between the first and second levels of current in response to the collector current.