Oscillation circuit, electronic circuit using the same, and semiconductor device, electronic equipment, and timepiece using the same

摘要

This invention provides a crystal oscillation circuit that is capable of operating stably with a low power consumption. This crystal oscillation circuit comprises a signal inversion amplifier and a power control circuit that controls the power voltage of this signal inversion amplifier in accordance with an oscillation output. The power control circuit comprises a power voltage generation circuit that outputs a plurality of power voltages of different values; a determination control portion that determines the optimal value of the power voltage to be applied to the signal inversion amplifier, based on the oscillation output; and a multiplexer that controls the switching of the power voltage applied to the signal inversion amplifier from the power voltage generation circuit, based on the result of that determination.