OSCILLATOR WITH DIGITAL TEMPERATURE COMPENSATION

摘要

The oscillator circuit comprises a digital temperature compensation circuit connected to a low and a high frequency quartz oscillator. The two quartz oscillators have the same inversion temperature points and a different temperature behaviour. In the temperature compensation circuit a beat frequency is produced between the divided signal of the high frequency oscillator and the frequency of the low frequency oscillator and then fed to a correction circuit and multiplied therein with a correction factor which has been stored in a PROM. The obtained correction signal is fed into the frequency divider chain for obtaining a temperature compensated outgoing signal for use in a timer circuit. The temperature compensation circuit is simply designed and allows high accuracy, which is particularly well suited for a wristwatch or a photo camera.