Pseudo-resistor structure, a closed-loop operational amplifier circuit and a bio-potential sensor

A pseudo-resistor structure, comprising:

• a first p-type metal-oxide-semiconductor (PMOS) transistor;
• a second PMOS transistor,
• wherein each of the first PMOS transistor and the second PMOS transistor have a drain terminal, a gate terminal, a source terminal and a bulk terminal with the gate terminal shorted with the drain terminal and a positive terminal and the source terminal shorted with the bulk terminal and a negative terminal, wherein the positive terminal of the first PMOS transistor is connected to the positive terminal of the second PMOS transistor and the negative terminal of the first PMOS transistor is connected to an input of the pseudo-resistor structure and wherein the negative terminal of the second PMOS transistor is connected to an output of the pseudo-resistor structure;
• and
• a dummy transistor connected to the input of the pseudo-resistor structure,
• wherein the dummy transistor is further connected to a bias voltage,
• wherein the dummy transistor is configured to compensate a leakage current through the first and the second PMOS transistors,
• wherein the dummy transistor comprises an n-type metal-oxide-semiconductor, NMOS, transistor formed in a deep n-type well.