Operational amplifier circuit, sample/hold circuit and filter circuit using the operational amplifier circuit

An operational amplifier circuit, comprising:

• a first inverted amplifier circuit that receives a first input signal;
• a second inverted amplifier circuit that receives a second input signal;
• a first non-inverted amplifier circuit that receives a common-mode input signal,
• a second non-inverted amplifier circuit that receives the common-mode input signal,
• a third inverted amplifier circuit that receives an estimated common-mode output signal and a sum of the output signal of the first non-inverted amplifier and the output signal of the first inverted amplifier circuit, and outputs a first output signal and a second output signal;
• and
• a fourth inverted amplifier circuit that receives the estimated common-mode output signal and a sum of the output signal of the second non-inverted amplifier and the output signal of the second inverted amplifier circuit, and outputs a third output signal and a fourth output signal,
• wherein adding the second output signal and the fourth output signal creates the estimated common-mode output signal.