Control circuit of pipeline ADC

A control circuit of a pipeline analog-to-digital converter (ADC), the pipeline ADC comprising a multiplying digital-to-analog converter (MDAC) which comprises a capacitor, the control circuit comprising:

• a first switch, coupled between a first end of the capacitor and a first reference voltage;
• a second switch, coupled between the first end of the capacitor and a second reference voltage;
• a third switch;
• a fourth switch;
• a fifth switch;
• a sixth switch;
• a first buffer circuit having a first input terminal and a first output terminal, wherein the first output terminal is coupled to the first switch, and the first input terminal is coupled to a third reference voltage through the third switch or receives a control signal through the fifth switch;
• and
• a second buffer circuit having a second input terminal and a second output terminal, wherein the second output terminal is coupled to the second switch, and the second input terminal is coupled to a fourth reference voltage through the fourth switch or receives the control signal through the sixth switch;
• wherein the first reference voltage is different from the second reference voltage, and the first switch and the second switch are not turned on simultaneously.