Patent ID: 8872684
Filing Date: 2014-10-28
Classification: H03H,H03M

Abstract:
1. A delta-sigma A/D converter comprising: a loop filter including a resonant filter and configured to receive a first input signal; a quantizer configured to convert an output of the loop filter into a digital signal; and a feedback D/A converter configured to convert an output of the quantizer into an analog signal and feed back the analog signal to the loop filter, wherein the resonant filter includes the resonant filter operates as an oscillator when the first switch is controlled to be on and therefore the output of the resonator is positively fed back to the input of the resonator through the feedback path, and as a filter when the first switch is controlled to be off and therefore the feedback path is open, and at least one of the resistor and the capacitor of the resonator is configured to allow a resistance value or a capacitance value thereof to be adjusted based on a third external signal.