Oscillation circuit and electronic circuit, and semiconductor device, timepiece and electronic equipment provided with the same

摘要

There is provided an oscillation circuit that enables oscillation at a stable frequency, unaffected by changes in the power-supply voltage of a main power source. An electrostatic protection circuit 200 provided for an oscillation circuit 40 includes a first electrostatic protection circuit section 210 connected between a signal path and the constant voltage Vreg side, which bypasses an electrostatic voltage of a first polarity that intrudes into the signal path to the constant bypass voltage Vreg side through a diode 72, and a second electrostatic protection circuit section 220 connected between the signal path and the ground side, which bypasses an electrostatic voltage of a second polarity that intrudes into the signal path to the ground side through a diode 74. The constant bypass voltage Vreg is set to a value such that the diode is not turned on by voltage change in the signal path caused by a leakage current, even when a leakage current is generated between the signal path and a power-supply voltage line.