Analog-to-digital converter comprising dual oscillators for linearity compensation
AssigneeWestern Digital Technologies, Inc.
InventorGeorge J. Bennett
Life of this patent
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Abstract
An analog-to-digital converter (ADC) is disclosed operable to convert a sensor signal to a digital value. A differential amplifier responsive to the sensor signal and a reference signal generates a first analog signal representing a first offset above the reference signal and a second analog signal representing a second offset below the reference signal. A first oscillator generates a first output frequency dependent on the first analog signal, and a second oscillator generates a second output frequency dependent on the second analog signal. A difference between the first output frequency and the second output frequency is generated, and the digital value representing the sensor signal is generated in response to the difference.
Claims18
An analog-to-digital converter (ADC) operable to convert a sensor signal to a digital value, the ADC comprising:
- a differential amplifier responsive to the sensor signal and a reference signal, the differential amplifier operable to generate a first analog signal representing a first offset above the reference signal and a second analog signal representing a second offset below the reference signal;
- a first oscillator comprising a first output frequency dependent on the first analog signal;
- a second oscillator comprising a second output frequency dependent on the second analog signal;
- and
- control circuitry operable to:
- generate a difference between the first output frequency and the second output frequency;
- and
- generate the digital value representing the sensor signal in response to the difference.
A method of converting a sensor signal to a digital value, the method comprising:
- generating a first analog signal representing a first offset above a reference signal and a second analog signal representing a second offset below the reference signal;
- using a first oscillator to generate a first output frequency dependent on the first analog signal;
- using a second oscillator to generate a second output frequency dependent on the second analog signal;
- generating a difference between the first output frequency and the second output frequency;
- and
- generating the digital value representing the sensor signal in response to the difference.
Dependencies are inferred from the claim text.