Oscillator circuit with an oscillating crystal

摘要

The invention relates to an oscillator with an oscillating crystal which is connected in series with a resistor which is small in comparison with the series resonant impedance. The series circuit is located in a feedback-type oscillator circuit and is driven by a low-impedance voltage source. The voltage picked up across the resistor is supplied to the transfer element following in the oscillator circuit. A controllable attenuator in the oscillator circuit is also included in an amplitude control loop. In addition, the oscillator circuit contains an electronically controllable phase rotator, with the aid of which the oscillator frequency can be pulled. This results in a relatively large pulling range with high spectral purity of the output signal.