DIGITAL TEMPERATURE COMPENSATION TYPE PIEZOELECTRIC OSCILLATOR

摘要

PURPOSE:To improve the frequency change due to invaded noise to an output of an A/D converter by adding an averaging circuit between the A/D converter and a memory. CONSTITUTION:The averaging circuit 3 is provided between the A/D converter 5 and the memory circuit 4 to absorb rapid digital code change in an output digital code of the circuit 3 because of noise. The output digital code of the circuit 3 is fed to the memory circuit 4. A temperature compensation digital code corresponding to the digital code being a temperature address signal is stored in advance in the memory circuit 4 to compensate the frequency temperature characteristic of a piezoelectric element used for a voltage controlled piezoelectric oscillator, the address signal is changed when the ambient temperature changes to read the temperature compensation digital code from the memory circuit 4.