Abstract: An analog to digital (A/D) converter includes a capacitor array having respective first terminals selectively coupled to a reference voltage or ground via a plurality of switches and having respective second terminals coupled to a sample and hold (S/H) output. The A/D converter also includes a voltage comparator having a first input coupled to the S/H output and having a second input coupled to a bias voltage. The voltage comparator is configured to output a comparison voltage responsive to a sampled charge at the S/H output and the bias voltage. The A/D converter also includes a successive approximation register coupled to receive the comparison voltage and configured to output an approximate digital code responsive to the comparison voltage, wherein the approximate digital code is varied by controlling an equivalent capacitance of the capacitor array.

Abstract: An analog to digital (A/D) converter includes a capacitor array having respective first terminals selectively coupled to a reference voltage or ground via a plurality of switches and having respective second terminals coupled to a sample and hold (S/H) output. The A/D converter also includes a voltage comparator having a first input coupled to the S/H output and having a second input coupled to a bias voltage. The voltage comparator is configured to output a comparison voltage responsive to a sampled charge at the S/H output and the bias voltage. The A/D converter also includes a successive approximation register coupled to receive the comparison voltage and configured to output an approximate digital code responsive to the comparison voltage, wherein the approximate digital code is varied by controlling an equivalent capacitance of the capacitor array.

Abstract: An analog-to-digital converter includes an input terminal, a digital-to-analog converter, a comparator, and successive approximation circuitry. The input terminal is configured to receive a multi-bit digital threshold value from circuitry external to the analog-to-digital converter. The successive approximation circuitry is coupled to the comparator and the digital-to-analog converter. The successive approximation circuitry is configured to operate in a comparison mode and a conversion mode, and to provide the multi-bit digital threshold value to the digital-to-analog converter while operating in the comparison mode. The comparator is coupled to the digital-to-analog converter and the successive approximation circuity. The comparator is configured to output a signal that indicates whether an analog input signal exceeds an analog threshold signal corresponding to the multi-bit digital threshold value.

Abstract: An analog-to-digital converter includes an input terminal, a digital-to-analog converter, a comparator, and successive approximation circuitry. The input terminal is configured to receive a multi-bit digital threshold value from circuitry external to the analog-to-digital converter. The successive approximation circuitry is coupled to the comparator and the digital-to-analog converter. The successive approximation circuitry is configured to operate in a comparison mode and a conversion mode, and to provide the multi-bit digital threshold value to the digital-to-analog converter while operating in the comparison mode. The comparator is coupled to the digital-to-analog converter and the successive approximation circuitry. The comparator is configured to output a signal that indicates whether an analog input signal exceeds an analog threshold signal corresponding to the multi-bit digital threshold value.