RC oscillator
AssigneeCatena Holding B.V.
InventorPeter van der Cammen
Life of this patent
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Abstract
The disclosure relates to a square wave RC oscillator circuit, example embodiments of which include an oscillator circuit for generating an output square wave signal (OUT) having first and second voltage output levels (L, H), the oscillator circuit comprising: a comparator having an output and first and second inputs; a switching circuit configured to provide an oscillatory waveform at the first input of the comparator; and a feedback circuit arranged to sample the first input of the comparator each time the output square wave signal (OUT) switches between the first and second voltage output levels (L, H) and to compare this sampled voltage with first and second reference voltages (VA, VB) to adjust a voltage provided to the second input of the comparator.
Claims13
An oscillator circuit configured to generate an output square wave signal having first and second voltage output levels, the oscillator circuit comprising:
- a single comparator having a single output and first and second inputs;
- a switching circuit configured to provide an oscillatory waveform at the first input of the comparator;
- and
- a feedback circuit configured
- to sample a voltage on the first input of the comparator in response to the output square wave signal switching between the first and second voltage output levels,
- to compare the voltage sample with first and second reference voltages, and
- to adjust a voltage provided to the second input of the comparator.
An oscillator circuit configured to generate an output square wave signal having first and second voltage output levels, the oscillator circuit comprising:
- a comparator having an output and first and second inputs;
- a switching circuit configured to provide an oscillatory waveform at the first input of the comparator;
- and
- a feedback circuit configured
- to sample a voltage on the first input of the comparator in response to the output square wave signal switching between the first and second voltage output levels,
- to compare the voltage sample with first and second reference voltages, and
- to adjust a voltage provided to the second input of the comparator;
- wherein the feedback circuit comprises:
- a sampler having an input connected to the output of the comparator and configured to provide,
- a first sampling pulse in response to the output of the comparator changing from the first voltage level to the second voltage level and
- a second sampling pulse in response to the voltage at the output of the comparator changing from the second voltage level to the first voltage level;
- a first amplifier having a first input coupled to the first input of the comparator via a third switch configured to close upon receiving the first sampling pulse from the sampler and a second input coupled to a first reference voltage source;
- a second capacitor coupled between the first input of the first amplifier and the common connection;
- a second amplifier having a first input coupled to the first input of the comparator via a fourth switch configured to close upon receiving the second sampling pulse from the sampler and a second input coupled to a second reference voltage source;
- a third capacitor connected between the first input of the second amplifier and the common connection;
- and
- a fifth switch coupled between the second input of the comparator and outputs of the first and second amplifiers;
- wherein the fifth switch is configured to alternately connect the second input of the comparator to the output of the first amplifier and the output of the second amplifier.
An oscillator circuit configured to generate an output square wave signal having first and second voltage output levels, the oscillator circuit comprising:
- a comparator having an output and first and second inputs;
- a switching circuit configured to provide an oscillatory waveform at the first input of the comparator;
- and
- a feedback circuit configured
- to sample a voltage on the first input of the comparator in response to the output square wave signal switching between the first and second voltage output levels,
- to compare the voltage sample with first and second reference voltages, and
- to adjust a voltage provided to the second input of the comparator;
- wherein the switching circuit is configured to provide a triangular waveform to the first input of the comparator.
Dependencies are inferred from the claim text.