Analog signal conditioning circuit having feedback offset cancellation
First Claim
1. Analog signal conditioning circuitry comprising:
- an amplifier having a first input receiving an analog input signal corresponding to an output signal generated by a sensor and a second input receiving a reference signal, said amplifier further comprising an output for providing an analog output signal defined by an amplified representation of the analog input signal and the reference signal; and
a feedback circuit having an input coupled to said amplifier output and an output coupled to the first input of the amplifier for providing an analog feedback signal thereto, said feedback circuit comprising an analog-to-digital converter for converting the analog amplifier output to a digital signal, a digital controller for processing the digital signal to compensate for offset in the analog output signal, and a digital-to-analog converter for converting the processed digital signal to the analog feedback signal, wherein the digital controller determines an amount of offset in the digital signal as compared to the reference signal and generates a processed digital feedback signal to compensate for the determined offset, and wherein the digital controller further for computing an average of digital signal outputs of the analog-to-digital converter and compensating for the determined offset when the difference between the average value and an expected value exceeds a predetermined value.
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Abstract
Analog signal conditioning circuitry is provided for processing an analog signal generated by a sensor to remove DC offset. The signal conditioning circuitry includes an amplifier having the first input receiving an analog input signal and a second input receiving a reference signal. The amplifier includes an output providing an analog output signal defined by an amplified representation of the analog input signal and the reference signal. The circuitry includes a feedback circuit having an input coupled to the amplifier output and an output coupled to the first input of the amplifier for providing an analog feedback signal. The feedback circuit includes an analog-to-digital converter for converting the analog amplifier output to a digital signal, a digital controller for processing the digital signal, and a digital to analog converter for converting the processed digital signal to an analog feedback signal.
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Citations
3 Claims
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1. Analog signal conditioning circuitry comprising:
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an amplifier having a first input receiving an analog input signal corresponding to an output signal generated by a sensor and a second input receiving a reference signal, said amplifier further comprising an output for providing an analog output signal defined by an amplified representation of the analog input signal and the reference signal; and
a feedback circuit having an input coupled to said amplifier output and an output coupled to the first input of the amplifier for providing an analog feedback signal thereto, said feedback circuit comprising an analog-to-digital converter for converting the analog amplifier output to a digital signal, a digital controller for processing the digital signal to compensate for offset in the analog output signal, and a digital-to-analog converter for converting the processed digital signal to the analog feedback signal, wherein the digital controller determines an amount of offset in the digital signal as compared to the reference signal and generates a processed digital feedback signal to compensate for the determined offset, and wherein the digital controller further for computing an average of digital signal outputs of the analog-to-digital converter and compensating for the determined offset when the difference between the average value and an expected value exceeds a predetermined value. - View Dependent Claims (2, 3)
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Specification