An apparatus comprises at least one transmit amplifier and rectification circuitry located in the at least one transmit amplifier, which is configured to receive a RF signal and provide a rectified voltage, which is selectably added to a voltage supplied by a battery to generate a DC voltage supply signal that is a function of RF power level. A controller is configured to select between providing the VBAT or the VSupply signal to a transmit switch depending on one or more of a logic state and a mode of operation. An alternate apparatus comprises a charge pump circuit configured to quickly raise a voltage supplied to it and store the output voltage on a capacitor and then either shift a first frequency provided by a charge pump oscillator to a lower second frequency or turn off a charge pump clock to maintain a voltage on the capacitor during a transmit mode.