Method and system for FET-based amplifier circuits

An amplifier circuit for amplifying a first signal to drive an output load, the circuit comprising:

• a field-effect transistor (FET) having a gate, a source and a drain;
• a switch arrangement coupled to the gate, the source and the drain;
• and
• state control logic that provides state information for a first state and a second state, wherein, in the first state, the first switch arrangement connects the first signal to the gate, the drain to a drain voltage and the source to source voltage and, in the second state, the switch arrangement disconnects the first signal from the gate, connects the drain to a voltage supply and connects the source to the output load, thereby causing the FET to operate in source-follower mode.

In an amplifier circuit, a method for amplifying a first signal using a field-effect transistor (FET), the method comprising:

• charging a gate of the FET to a voltage responsive to the first signal;
• driving a source of the FET to a first reference voltage;
• driving a drain of the FET to a second reference voltage;
• and
• placing the FET in source-follower mode by disconnecting the gate from the first signal, connecting the drain to a third reference voltage and connecting the source to an output load, wherein the FET drives the output load to a voltage that is a function of the first signal, a capacitance from gate to source, a capacitance from gate to drain and the first signal.