Abstract: 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.

Abstract: An oscillator circuit having a digital temperature compensation circuit which contains two low frequency quartz oscillators, a beat frequency generator and a correction circuit and a logic circuit selectively controlling an addition circuit. The beat frequency generator receives the frequencies generated by the low frequency oscillators. The difference between the low frequencies is fed into the correction circuit which in turn cooperates with the logic circuit. The beat frequency generator is controlled by a high frequency oscillator having an integrated RC circuit and the correction circuit has a PROM in which the correction functions are stored. The selectively controlled addition circuit acts on the output signal of the first oscillator and corrects the frequency thereof.

Abstract: A signal generator having a digital temperature compensation circuit contains high and low frequency quartz oscillators (HF and NF), the low frequency oscillator being used for temperature compensation. Both oscillators are manufactured such that the descending portion of the temperature dependent parabolic frequency curve of the low frequency oscillator passes through the temperature inversion point of the parabola of the high frequency oscillator.The frequencies of both oscillators are first adjusted such that the ratio thereof is inversely proportional to the ratio of the parabolic temperature coefficient, i.e., f.sub.1 :f.sub.2 =.beta..sub.2 :.beta..sub.1. Subsequently two substantially identical reference frequencies are adjusted and, by feeding back the output frequency, combined in such a manner that an output frequency independent of temperature is produced which is determined substantially by the high frequency oscillator.