High efficiency linear amplifier

摘要

A linear amplifier is configured with a current-feedback amplifier followed by a voltage-feedback amplifier to drive a totem-pole output stage. The output stage includes a series arrangement of an npn transistor and a pnp transistor with their emitters coupled in series and to an output node. The voltage amplifier driving the output stage is also configured with totem-pole elements, wherein a conductive path between the voltage-feedback amplifier and an output transistor is included to reduce conduction of the output transistor when the opposing output transistor is driven to increase conduction as a result of a high-frequency input signal. A capacitor may be included between the collector and base of a transistor in the circuit path that drives an output transistor in the output stage to briefly reduce its conduction when the opposing output transistor is driven to increase conduction.