Crystal oscillator with self-adaptive amplifier conduction angle control
AssigneeThe Hong Kong University of Science and Technology
InventorsYihan ZHANG, Manyu WANG, Peng WANG
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Abstract
The present invention provides a crystal oscillator using a digitally defined conduction angle that is adaptive to the current oscillation amplitude to operate the crystal oscillator's sustaining amplifier in a Class-C fashion. System-level simulation shows 80% to 90% power efficiency when using a θ-modulated subthreshold inverter. It is also demonstrated that the conduction-angle-adaptive crystal oscillator can reduce the circuit's power consumption at small chip area while preserving an intrinsic start-up capability.
Claims15
A crystal oscillator with self-adaptive amplifier conduction angle control, comprising:
- a crystal resonator having a pair of first and second terminals;
- an oscillation amplifier having an input terminal and an output terminal connected to the first terminal and the second terminal of the crystal resonator, respectively;
- a high-side power-gating switch connected between a first reference terminal of the oscillation amplifier and a first reference voltage;
- a low-side power-gating switch connected between a second reference terminal of the oscillation amplifier to a second reference voltage;
- a high-side oscillation amplitude detector having:
- a first high-side sensing input terminal and a second high-side sensing input terminal connected to the first terminal and the second terminal of the crystal resonator, respectively;
- a high-side driver having a high-side driver input terminal connected to a high-side sensing output terminal of the high-side oscillation amplitude detector;
- and a high-side driver output terminal connected to a control terminal of the high-side power-gating switch;
- a low-side oscillation amplitude detector having:
- a first low-side sensing input terminal and a second low-side sensing input terminal connected to the first terminal and the second terminal of the crystal resonator, respectively;
- and a low-side driver having a low-side driver input terminal connected to a low-side sensing output terminal of the low-side oscillation amplitude detector;
- and a low-side driver output terminal connected to a control terminal of the low-side power-gating switch.
Dependencies are inferred from the claim text.