Digital envelop tracker for power amplifier

A digital envelop tracker circuitry, comprising:

• a level selection circuitry configured to determine a level of supply voltage based on a power of an input data stream and generate a level select signal,
• wherein the level select signal is generated based on a series of voltage level switching events triggered by each determined level of supply voltage,
• wherein the level selection circuitry comprises:
• a primary switching circuitry configured to schedule a primary switching event of the switch based on the determined level of supply voltage,
• a secondary switching circuitry configured to schedule secondary switching events of the switch at time instances delayed from the primary switching event based on the determined level of supply voltage, and
• a combiner configured to combine the primary switching event and previously scheduled secondary switching events to generate the level select signal, and
• a switch configured to connect one of a plurality of supply voltages in different levels to a supply filter based on the level select signal.