Patent ID: 6097257
Filing Date: 2000-08-01
Classification: G04F,G04G,G05F,H03B,H03K

Abstract:
An oscillation circuit comprising:a signal inversion amplifier comprising a first transistor and a second transistor;a feedback circuit having a crystal oscillator, for inverting the phase of an output signal of said signal inversion amplifier and feeding said inverted signal back as an input to said signal amplifier; anda control circuit for controlling a back gate voltage between the back gate and source of said second transistor;wherein the back gate of said second transistor is set to a predetermined potential; andwherein said control circuit comprises:a rectifier element circuit connected to the source of said second transistor;a switching element that forms a bypass circuit for said rectifier element circuit; anda switching circuit for selectively switching a back gate voltage of said second transistor over at least two stages, by on/off control of said switching element.