Low-quiescent current headset driver

摘要

A low quiescent current amplifier and driver (100) having multiple amplifiers (e.g. Class AB and B amplifiers) work in concert to independently amplify all or a portion of a signal into multiple amplified signals combined into a unified signal. Operation of a second amplifier (111) is slaved to operation of a first amplifier (gm). Each amplifier may have its own feedback loop providing the same gain transfer function to align transitions of the multiple amplified signals. Operation of the first amplifier may be detected using a replica of a signal, stage or transconductance in the first amplifier. At the same threshold, operation of the first and second amplifiers may be transitioned, e.g., the second amplifier may transition between providing increasing or decreasing current and providing zero current while the first amplifier may transition between providing constant current and providing increasing or decreasing current.