Open loop digital PWM envelope tracking system with dynamic boosting

A transmitter comprising:

• a power terminal configured to deliver an available supply voltage from an available power source for use by the transmitter;
• a boost circuit coupled to the power terminal and configured to generate a boosted supply voltage greater than the available supply voltage;
• an envelope generator configured to receive a data signal to be transmitted by the transmitter and generate an envelope signal;
• a pulse width modulation (PWM) generator configured to receive the envelope signal and output a PWM signal;
• an envelope tracking (ET) modulator coupled to the PWM generator and configured to modulate an ET modulator input supply voltage;
• a controller configured to receive the envelope signal and a signal indicative of the available power supply voltage and generate a dynamic boost enable/disable signal in response thereto;
• and
• a switching circuit coupled to the available supply voltage and the boosted supply voltage and configured to select and input either the available supply voltage or the boosted supply voltage as the ET modulator input supply voltage.

A method of dynamically boosting a supply input voltage to a power amplifier (PA) comprising:

• receiving, at a transmitter, a data signal to be transmitted;
• generating, by the transmitter, an envelope signal based on the received data signal;
• generating a pulse width modulation (PWM) signal, based on the envelope signal;
• receiving the pulse width modulation (PWM) signal;
• based on an envelope tracking (ET) modulator boost enable signal, receiving one of a first supply voltage or a second supply voltage, the second supply voltage being greater than the first supply voltage;
• generating a sense signal representative of the first supply voltage;
• and
• receiving the sense signal and a boost signal representative of the second supply voltage and selectively outputting the sense signal or the boost signal in response to the ET modulator boost enable signal;
• and
• outputting, by the transmitter, a power amplifier (PA) switching supply source.