Oscillator circuit having an expanded operating range

摘要

An oscillator circuit having an expanded operating range includes an amplifier portion amplifying an oscillating signal. A gain controlling portion controls the gain of the amplified oscillating signal. A switching circuit electrically connected across the gain controlling portion provides a low impedance electrical path in parallel with the gain controlling portion in response to a switch input signal. The switching circuit further includes a switch signal generator portion producing the switch input signal to switch the switching circuit ON or OFF when power supplied to the oscillator circuit reaches a first predetermined voltage level and to switch the switching circuit OFF or ON when power supplied to the oscillator circuit reaches a second predetermined voltage level. In this circuit design, the initiation of an oscillating signal by the oscillator circuit is unaffected by supply voltage variation or, in other words, fluctuation in the power supplied to the oscillator circuit.