Switched oscillator circuit
AssigneeNordic Semiconductor ASA
InventorsCheng-Hsueh Tsai, Henrik Fon
Life of this patent
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Abstract
An oscillator circuit portion 200 including a resonator 216 arranged to oscillate with a resonant frequency, a capacitor 208 arranged to provide charge to the resonator, a first switch 206 arranged to connect the capacitor to an input voltage to charge the capacitor, a second switch 210 arranged to connect the resonator to the capacitor, and a timing circuit 202 configured to generate periodically a first pulse PULSE_L and a second pulse PULSE_H. The first pulse is configured to close the first switch, the second pulse is configured to close the second switch, and the first and second switches are arranged to be open when the timing circuit is not generating the first or second pulses, to maintain oscillation of the resonator.
Claims13
An oscillator circuit portion, comprising:
- a resonator arranged to oscillate with a resonant frequency;
- a capacitor arranged to provide charge to the resonator;
- a first switch arranged to connect the capacitor to an input voltage to charge the capacitor;
- a second switch arranged to connect the resonator to the capacitor;
- a third switch arranged to connect the resonator to ground;
- and
- a timing circuit configured to generate periodically a first pulse and a second pulse;
- wherein the first pulse is configured to close the first switch;
- wherein the second pulse is configured to close the second switch;
- wherein the first and second switches are arranged to be open when the timing circuit is not generating the first or second pulses, to maintain the oscillation of the resonator;
- and
- wherein the first pulse is configured to close the third switch.
An oscillator circuit portion, comprising:
- a resonator arranged to oscillate with a resonant frequency;
- a capacitor arranged to provide charge to the resonator;
- a first switch arranged to connect the capacitor to an input voltage to charge the capacitor;
- a second switch arranged to connect the resonator to the capacitor;
- and
- a timing circuit configured to generate periodically a first pulse and a second pulse;
- wherein the first pulse is configured to close the first switch;
- wherein the second pulse is configured to close the second switch;
- wherein the first and second switches are arranged to be open when the timing circuit is not generating the first or second pulses, to maintain the oscillation of the resonator;
- and
- wherein the capacitor is arranged to partially charge the resonator during the second pulse.
An oscillator circuit portion, comprising:
- a resonator arranged to oscillate with a resonant frequency;
- a capacitor arranged to provide charge to the resonator;
- a first switch arranged to connect the capacitor to an input voltage to charge the capacitor;
- a second switch arranged to connect the resonator to the capacitor;
- and
- a timing circuit configured to generate periodically a first pulse and a second pulse;
- wherein the first pulse is configured to close the first switch;
- wherein the second pulse is configured to close the second switch;
- wherein the first and second switches are arranged to be open when the timing circuit is not generating the first or second pulses, to maintain the oscillation of the resonator;
- and
- wherein the capacitor is arranged to partially charge during the first pulse.
An oscillator circuit portion, comprising:
- a resonator arranged to oscillate with a resonant frequency;
- a capacitor arranged to provide charge to the resonator;
- a first switch arranged to connect the capacitor to an input voltage to charge the capacitor;
- a second switch arranged to connect the resonator to the capacitor;
- and
- a timing circuit configured to generate periodically a first pulse and a second pulse;
- wherein the first pulse is configured to close the first switch;
- wherein the second pulse is configured to close the second switch;
- wherein the first and second switches are arranged to be open when the timing circuit is not generating the first or second pulses, to maintain the oscillation of the resonator;
- and
- wherein the capacitor is a variable capacitor.
A method of operating an oscillator circuit portion comprising:
- oscillating a resonator with a resonant frequency;
- using a capacitor to provide charge to the resonator;
- charging the capacitor from an input voltage;
- generating periodically a first pulse and a second pulse using a timing circuit;
- closing a first switch between the capacitor and the input voltage during the first pulse;
- closing a second switch between the resonator and the capacitor during the second pulse;
- opening the first and second switches when the timing circuit is not generating the first or second pulses, maintaining the oscillation of the resonator;
- and
- closing a third switch between the resonator and ground during the first pulse.
A method of operating an integrated circuit comprising an oscillator circuit, the method comprising:
- oscillating a resonator with a resonant frequency;
- using a capacitor to provide charge to the resonator;
- charging the capacitor from a voltage supply of the integrated circuit;
- generating periodically a first pulse and a second pulse using a timing circuit;
- closing a first switch between the capacitor and the voltage supply during the first pulse;
- closing a second switch between the resonator and the capacitor during the second pulse;
- opening the first and second switches when the timing circuit is not generating the first or second pulses, maintaining the oscillation of the resonator;
- and
- closing a third switch between the resonator and ground during the first pulse.
Dependencies are inferred from the claim text.