Integrated Circuit Amplifier with Gate Tunneling Resistor

An integrated circuit amplifier apparatus comprising:

• a fully differential operational amplifier having differential voltage inputs, a first differential output, and a complementary second differential output;
• a first feedback capacitor coupled from the first differential output to one of the inputs;
• a first feedback field effect transistor (FET) configured as a gate tunneling resistor in parallel with the first feedback capacitor;
• a second feedback capacitor coupled from the second differential output to the other of the differential voltage inputs, the second feedback capacitor having a same capacitance as the first feedback capacitor;
• and
• a second feedback FET configured as a gate tunneling resistor in parallel with the second feedback capacitor.

A method of manufacturing an integrated circuit amplifier, the method comprising:

• providing a fully differential operational amplifier having differential voltage inputs, a first differential output, and a complementary second differential output;
• coupling a first feedback capacitor from the first differential output to one of the inputs;
• coupling a first feedback field effect transistor (FET), configured as a gate tunneling resistor, in parallel with the first feedback capacitor, wherein the first FET has a gate, a source, and a drain, the configuring including coupling the gate to one of the differential voltage inputs, and coupling the source and the drain together and to the first differential output;
• coupling a second feedback capacitor connected from the second differential output to the other of the differential voltage inputs, the second feedback capacitor having a same capacitance as the first feedback capacitor;
• and
• coupling a second feedback FET configured as a gate tunneling resistor in parallel with the second feedback capacitor.