Multistage amplifying circuit

A multistage amplifying circuit comprising:

• a common amplifying circuit that receives a first input voltage and a second input voltage, wherein the common amplifying circuit is configured to alternatively in response to a control signal:
• reset the first input voltage and amplify the second input voltage, or
• reset the second input voltage and amplify the first input voltage;
• a first control circuit that, alternatively in response to the control signal:
• samples a first analog voltage input to the first control circuit, or
• amplifies the first input voltage as a difference between the first analog voltage and a first digital voltage converted from the first analog voltage by using the common amplifying circuit,
• to determine an output voltage of the common amplifying circuit;
• and
• a second control circuit that, alternatively in response to the control signal:
• samples a second analog voltage input to the second control circuit, or
• amplifies the second input voltage as a difference between the second analog voltage and a second digital voltage converted from the second analog voltage by using the common amplifying circuit,
• to determine an output voltage of the common amplifying circuit,
• wherein the first control circuit and the second control circuit complement each other.

A multistage amplifier circuit comprising:

• a first amplifying circuit that, in response to a control signal, either samples a first analog voltage input or amplifies a difference between the first analog voltage and a first digital voltage converted from the first analog voltage;
• a second amplifying circuit that, in response to the control signal, either samples a second analog voltage input or amplifies a difference between the second analog voltage and a second digital voltage converted from the second analog voltage;
• and
• a common amplifier that, in response to the control signal, receives output voltages of the first amplifying circuit and the second amplifying circuit and either:
• resets the output voltage of the first amplifying circuit and determines an output voltage of the multistage amplifier circuit by using the second amplifying circuit, or
• resets the output voltage of the second amplifying circuit and determines an output voltage of the multistage amplifier circuit by using the first amplifying circuit.