Quadrature noise shapingsar ADC and operation method thereof

An operation method of a noise shaping successive approximation register analog-to-digital converter (NS-SAR ADC), comprising:

• sampling an in-phase input signal by a first Capacitive Analog-to-Digital Converter (CADC) of a first successive approximation register analog-to-digital converter (SAR ADC) and a quadrature input signal by a second CADC of a second SAR ADC;
• converting the in-phase input signal sampled by the first CADC and the quadrature input signal sampled by the second CADC into digital signals using a first comparator and a second comparator, respectively;
• and
• integrating, a combined signal of an in-phase residue remaining in the first CADC and a first cross-couple residue transmitted from the second CADC by a first integrator, and a combined signal of a quadrature residue remaining in the second CADC and a second cross-couple residue transmitted from the first CADC, respectively.

An analog-to-digital converter, comprising:

• a first noise shaping successive approximation register analog-to-digital converter (NS-SAR ADC) configured to convert an in-phase input signal into digital data;
• and
• a second noise shaping successive approximation register analog-to-digital converter (NS-SAR ADC) configured to convert a quadrature input signal into digital data,
• wherein the first NS-SAR ADC integrates a first residue obtained by subtracting an in-phase output from the in-phase input signal, and the second NS-SAR ADC integrates a second residue obtained by subtracting a quadrature output from the quadrature input signal,
• wherein a portion of the first residue is transmitted to the second NS-SAR ADC, and a portion of the second residue is transmitted to the first NS-SAR ADC.