Amplifier

An amplifier comprising:

• a first input transistor having a first gate connected to a first input, a first drain connected to a first output, and a first source connected to a power source;
• a second input transistor having a second gate connected to a second input, a second drain connected to a second output, and a second source connected to the power source;
• a first replica transistor having a third gate connected to the first input, a third drain connected to a detection node, and a third source connected to the power source;
• a second replica transistor having a fourth gate connected to the second input, a fourth drain connected to the detection node, and a fourth source connected to the power source;
• and
• a bias transistor having a fifth gate connected to a bias voltage, a fifth drain connected to the detection node, and a fifth source connected to a ground.

An amplifier comprising:

• a first input transistor having a first gate connected to a first input, a first drain connected to a first output, and a first source connected to a ground;
• a second input transistor having a second gate connected to a second input, a second drain connected to a second output, and a second source connected to the ground;
• a first replica transistor having a third gate connected to the first input, a third drain connected to a detection node, and a third source connected to the ground;
• a second replica transistor having a fourth gate connected to the second input, a fourth drain connected to the detection node, and a fourth source connected to the ground;
• and
• a bias transistor having a fifth gate connected to a bias voltage, a fifth source connected to the detection node, and a fifth drain connected to a power source.

A method of operating an amplifier comprising:

• obtaining a detection voltage or a detection current at a detection node of the amplifier;
• adjusting input values of a first internal input and a second internal input of the amplifier based on the obtained detection current or the obtained detection voltage;
• and
• feeding back the adjusted input values of the first internal input and the second internal input as the input values of the amplifier such that the obtained detection current or the detection voltage corresponds to a target voltage or a target current,
• wherein the detection voltage or the detection current of the detection node is determined by drain currents of a first replica transistor and a second replica transistor of the amplifier.