OUTPUT COUPLING CAPACITOR FREE AUDIO POWER AMPLIFIER DYNAMICALLY CONFIGURED FOR SPEAKERS AND HEADPHONES WITH EXCELLENT CLICK AND POP PERFORMANCE

摘要

First and second channel bridge amplifiers are dynamically configured to drive either speakers or headphones. The first channel bridge amplifier includes a first amplifier driving one end of a first speaker through a mechanical switch in a headphone-jack, and a second amplifier driving another end of the first speaker. The second channel bridge amplifier includes third and fourth amplifiers driving respective ends of a second speaker. To suppress click and pop, an amplifier control circuit maintains certain amplifiers (depending on headphone or speaker mode) tri-stated until input coupling capacitors have fully charged and an input signal exceeding a predetermined amount is detected.