Device and method for controlling power amplifier

A control device configured to provide a supply voltage to an output transistor of a power amplifier configured to amplify an input signal, the control device comprising:

• a detector encoder configured to receive a detection signal indicating a negative peak voltage level of an output signal of the power amplifier, to receive a reference signal indicating a critical voltage of the detection signal at which the negative peak voltage level of the output transistor is deemed to be out of voltage with reference to saturation voltage of the output transistor, to compare the detection signal and the reference signal, and to output a Boost Request signal and a Recovery Request signal in response to the comparison;
• a switch sequencer configured to translate the Boost Request signal and the Recovery Request signal into a plurality of control bits;
• and
• a power switch configured to coordinate switching among a no boost voltage and a plurality of different boost voltages based on the plurality of control bits, and to output one of the no boost voltage and the plurality of different boost voltages as the supply voltage to the output transistor.