Multiplying digital-to-analog converter (MDAC) and capacitor switching amplifier circuit thereof

A multiplying digital-to-analog converter (MDAC) having a first input terminal, a second input terminal, a first output terminal, and a second output terminal, the MDAC comprising:

• an analog-to-digital converter (ADC) coupled to the first input terminal and the second input terminal and configured to generate a selection signal according to a first input signal and a second input signal;
• a selection circuit coupled to the ADC and configured to select a first reference voltage and a second reference voltage from a plurality of preset voltages according to the selection signal;
• a first sampling and amplifying circuit coupled to the selection circuit and the first input terminal and configured to sample and amplify the first input signal according to the first reference voltage;
• a second sampling and amplifying circuit coupled to the selection circuit and the second input terminal and configured to sample and amplify the second input signal according to the second reference voltage;
• an operational amplifier coupled to the first sampling and amplifying circuit and the second sampling and amplifying circuit and having a first output node and a second output node;
• and
• an amplification and level shifting circuit coupled to the first output node, the second output node, the first output terminal, the second output terminal, the first input terminal, the second input terminal, and the selection circuit and configured to amplify the first input signal and the second input signal and to level shift a voltage at the first output node and a voltage at the second output node.