US Patent 9596110 Open loop digital PWM envelope tracking system with dynamic boosting

A system, apparatus and method is described for dynamically boosting (increasing) the power supply voltage to an envelope tracking (ET) modulator within a transmitter system when the target/desired power amplifier voltage supply is above a predetermined threshold (e.g., equal to the available power supply of the system, such as a battery). By boosting the power input supply to the ET modulator, the modulated power supply provided to the power amplifier (PA) is also increased. This reduces or eliminates clipping that normally occurs when the target/desired PA supply voltage is greater than the available power supply voltage and reduces distortion in the transmitted signal.