OSCILLATION CIRCUIT

PURPOSE:To reset an oscillation circuit to a stationary oscillation state early without increasing an oscillation circuit current by turning off a switching element and reducing a capacity value at the start of oscillation, and turning on the switching element and increasing the capacity value during stationary oscillation. CONSTITUTION:A voltage is impressed between power lines VDD and VSS, the signal of the power line VSS is supplied to an input terminal 8 as a control signal at the start of oscillation accompanying this voltage impression, and only a capacitor 5 is provided as a capacity element provided to the input part of the inverter composed of complementary MOSFETs 2 and 3. Consequently, the loop gain of the oscillation circuit increases and the oscillation becomes easy to start. The signal of the power line VDD is supplied as a control signal to the input terminal 8 after the oscillation starts and capacitors 5 and 7 are connected as capacity elements provided to the input part of the inverter composed of the complementary MOSFETs 2 and 3 to enter the stationary oscillation state early.