Patent ID: 11900879
Assignee: APPLE INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A sensing circuit comprising:
a differential amplifier configured to receive an input signal;
a first capacitor coupled to the differential amplifier;
a second capacitor coupled to the first capacitor;
an analog-to-digital converter (ADC) coupled to the differential amplifier,
wherein, during a first portion of a measurement cycle:
the second capacitor is connected in parallel with the first capacitor, the first capacitor connected between a first input terminal and a first output terminal of the differential amplifier, and
the ADC is configured to sample a differential output of the differential amplifier for obtaining a first set of measurements, and

wherein, during a second portion of the measurement cycle:
the second capacitor is disconnected from the first capacitor, and
the ADC is configured to sample the differential output of the differential amplifier for obtaining a second set of measurements; and

an average value calculator circuit coupled to the ADC and configured to determine a characteristic of the input signal by determining an average of an output of the sensing circuit during the measurement cycle calculated based on the first set of measurements and the second set of measurements.