| CPC H03M 1/0682 (2013.01) [H03M 1/002 (2013.01)] | 16 Claims |

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1. A successive approximation register (SAR) analog-to-digital converter (ADC), comprising:
a plurality of differential capacitive digital-to-analog converters (C-DACs), wherein each differential C-DAC comprises a pair of C-DACs for positive and negative polarities and each C-DAC comprises a capacitor array including a plurality of capacitors coupled in parallel to an output node of each C-DAC, wherein a capacitor for each bit position in each C-DAC comprises a pair of equal-sized capacitors;
a plurality of comparators including two or more outer comparators and at least one middle comparator, wherein each outer comparator is coupled to one of the differential C-DACs and the middle comparator is coupled to a differential output node pair of C-DACs from two differential C-DACs; and
an SAR controller configured to generate a control signal for the plurality of differential C-DACs for each conversion step based on outputs of the comparators,
wherein the SAR controller is configured to perform one or more multi-bit per cycle conversions and then at least one single-bit per cycle conversion for converting an analog input signal to a digital signal, wherein the outputs of the comparators are provided to the differential C-DACs as the control signal without encoding.
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