US Patent 9516693 Fast transition envelope tracking

Envelope power supply circuitry is operated in one of an off-state, a standby-state, and a transmit-state. In the standby-state, select components in envelope power converter circuitry in the envelope power supply circuitry are turned on in order to charge one or more inductive and/or capacitive elements therein to a maximum value necessary for supporting transmission of signals about a maximum output power. Accordingly, the envelope power supply circuitry is able to prepare to support transmission about any output power without knowing the output power ahead of time.