Power amplifier with automatic switching function

Abstract

A power amplifier with automatic switching functions is disclosed. The power amplifier can variably control output power of circuits as all of the circuits are operated when relatively large power is needed, and the circuits are partially turned off when relatively small power is needed, according to magnitude of an envelope signal, such that the circuits can be smoothly and automatically switched so as not to affect operations of the circuit, and to improve efficiency and operation range thereof, as parts of the circuit can be turned off/on depending on magnitudes of output power.