Patent ID: 8868022

Claim:
A transconductance amplifier having an input terminal for receiving an input signal and an output terminal for communicating an output signal based on the input signal, the transconductance amplifier comprising: a gain transistor having a gate terminal, a first non-gate terminal, and a second non-gate terminal, the first non-gate terminal coupled to the output terminal of the transconductance amplifier; and a variable capacitance coupled between the gate terminal of the gain transistor and the second non-gate terminal of the gain transistor, the variable capacitance comprising: a non-switched capacitor coupled between the gate terminal of the gain transistor and the second non-gate terminal of the gain transistor; a switched capacitor having a first terminal and a second terminal; and a switching transistor having a gate terminal, a first non-gate terminal, and a second non-gate terminal, the first non-gate terminal coupled to the first terminal of the switched capacitor, and the gate terminal of the switching transistor coupled to a control terminal of the transconductance amplifier for receiving a control signal; wherein one of the second terminal of the switched capacitor and the second non-gate terminal of the switching transistor is coupled to the gate terminal of the gain transistor and the other of the second terminal of the switched capacitor and the second non-gate terminal of the switching transistor is coupled to the second-non gate terminal of the gain transistor.