Patent ID: 8258876

Claim:
A circuit for power amplification, the circuit comprising: a. a power amplifier, the power amplifier having an input port and an output port, the power amplifier having at least one transistor, and a current mirror is coupled between a base terminal of the at least one transistor and a ground node; and b. a protection circuit connected as a negative feedback loop around the power amplifier, the protection circuit including: i. a detector circuit configured to detect an output voltage from the output port, wherein the detector circuit provides a driver signal when the output voltage exceeds a predefined threshold; ii. a driver circuit configured to receive the driver signal from the detector circuit, wherein the driver circuit is configured to adjust a gain and phase margin of the negative feedback loop to maintain stability, and wherein the driver circuit includes a filter circuit that provides a filtered signal; and iii. an attenuator circuit coupled with the input port and the driver circuit, wherein the attenuator circuit is configured to receive the filtered signal from the filter circuit and attenuate an input voltage at the input port, wherein attenuation in the input voltage results in reduction of the output voltage below the predefined threshold.