JPS6458103A - Piezoelectric oscillator with temperature compensation - Google Patents

Abstract

PURPOSE:To facilitate temperature compensation by providing 1st and 2nd memory circuits storing a digital code respectively applying temperature compensation of 1st and 2nd change elements, an A/D converter receiving alternately the output, a switching circuit switching the input/output synchronously and two sample-hold circuits receiving the two outputs of said converter. CONSTITUTION:A temperature compensation digital code is fed to memory circuits 3, 13, and the output of the circuits 3, 13 is switched by a switching circuit 14, given to an A/D conversion circuit 4, its output is switched synchronously with the input. The two outputs are fed to a voltage controlled piezoelectric oscillator 5 via sample-hold circuits 19, 20. The circuit 3 uses said code as the address to store the frequency temperature compensation digital code corresponding thereto. When the ambient temperature varies, the address signal is changed and the code of the circuit 3 is read, converted into an analog signal and fed to a frequency control terminal 17 of the oscillator 5. The circuit 13 stores an output voltage temperature compensation digital code and when the ambient temperature charges, the address signal is changed, the code of the circuit 13 is read and converted into an analog signal and fed to the output voltage control terminal 18 of the oscillator 5.