SAR ADCDelta-Sigma ADC using SAR quantizer

摘要

Disclosed is a delta sigma ADC using an SAR quantizer. The disclosed delta sigma ADC comprises: a loop filter unit; a successive approximation register (SAR) quantizer unit which receives an output signal of the loop filter unit and outputs a first output signal and a second output signal; a digital filter unit which performs a digital filtering for the second output signal; and a subtractor A which receives the first output signal through a positive (+) input terminal and an output signal of the digital filter unit through a negative (-) input terminal. The loop filter unit receives an analog signal and the first output signal. The output signal of the subtractor A is an output signal of the delta sigma ADC. The first output signal is most significant bits (MSBs) among result values quantized in the SAR quantizer unit, and the second output signal is least significant bits (LSBs) among result values quantized in the SAR quantizer unit. Due to the use of the SAR quantizer, the present invention minimizes problems occurring in a process of generating quantization noise and easily reduces the quantization noise in a final output.