Back to results
US 4,536,721 AGranted
Low noise crystal oscillator
AssigneeAdret Electronique
InventorRoger Charbonnier
Life of this patent
Estimating the term…
Abstract
A crystal oscillator comprises an active coupling member driving the series mode resonance of a piezoelectric crystal proportionally to a feedback voltage. Said coupling member is followed by a current boosting transformer whose secondary winding is connected to an output amplifier and to a clipping amplifier shunted across said secondary winding and itself followed by a band-pass filter which supplies said feedback voltage to said coupling member.
Claims4
An oscillator comprising:
- a crystal resonator;
- active coupling circuit means having first and second inputs and an output, the first input being connected to the crystal resonator;
- a current booster transformer having primary and secondary windings, the primary winding being connected to the output of the coupling circuit means;
- output amplifier means connected in series with the secondary winding;
- amplitude limiting amplifier means connected in parallel across the secondary winding said amplitude limiting amplifier means having an output;
- and
- band-pass filter means connecting the output of said amplitude limiting amplifier means to the said second input.
4 more elements
Dependencies are inferred from the claim text.