Apparatus and methods for capacitive load reduction

摘要

Apparatus and methods for capacitive load reduction are disclosed. In one embodiment, a power amplifier system includes an envelope tracker configured to provide a supply voltage to a plurality of power amplifiers. The power amplifiers include power supply inputs electrically connected in a star configuration so as to reduce a capacitive load of the envelope tracker. The distributed capacitance of the power amplifiers is used to provide RF grounding so as to reduce the size of or eliminated the use of bypass capacitors.

主权项

1. A mobile device comprising:
a phone board; a multi-chip module disposed on the phone board, the multi-chip module including a plurality of power amplifiers formed on one or more power amplifier dies, the plurality of power amplifiers including at least three power amplifiers, each power amplifier having a supply input for receiving a power supply, the supply inputs of the plurality of power amplifiers electrically connected to one another by a first power supply network of the multi-chip module such that interconnect associated with each of the supply inputs of the power amplifiers meets at a first node, each of the plurality of power amplifiers including a first stage and a second stage, the first stage configured to drive the second stage, each of the plurality of power amplifiers including a first stage supply input, the first stage supply inputs electrically connected to a second power supply network such that interconnect associated with each of the first stage supply inputs of the power amplifiers meets at a second node; and an envelope tracking module disposed on the phone board, the envelope tracking module electrically connected to the first power supply network and configured to control a voltage level of the first power supply network, the envelope tracking module configured to electrically power the second stage of each of the plurality of power amplifiers.