OSCILLATED FREQUENCY CONTROL METHOD, VOLTAGE CONTROLLED PIEZOELECTRIC OSCILLATOR, VOLTAGE CONTROLLED PIEZOELECTRIC OSCILLATOR ADJUSTMENT SYSTEM AND METHOD FOR ADJUSTING VOLTAGE CONTROLLED PIEZOELECTRIC OSCILLATOR

摘要

PROBLEM TO BE SOLVED: To provide a voltage controlled piezoelectric oscillator circuit that does not employ a variable capacitor and a trimmer. ;SOLUTION: A variable voltage generating circuit 10 applies a power supply voltage VDD that is adjusted in response to a control voltage Vc to an oscillation circuit 20. A frequency adjustment circuit 30 adjusts a center of oscillated frequencies of the oscillation circuit 20. Furthermore, a memory 60 stores frequency setting data and voltage gradient data and the data are fed to a variable voltage generating circuit 10 and the frequency adjustment circuit 30 via a control circuit 50. When the power supply voltage VDD of the oscillation circuit 20 is fluctuated, since a parasitic capacitance depending on the voltage changes, the oscillated frequency of an oscillated signal SOSC is varied.;COPYRIGHT: (C)2000,JPO