Maxim Integrated's MAX97000 and MAX97001 audio subsystem ICs combine a mono speaker amplifier with a stereo headphone amplifier and an analog DPST switch. The headphone and speaker amplifiers of these Maxim Integrated devices have independent volume control and on/off control. The four inputs are configurable as two differential inputs or four single-ended inputs. The MAX97000 and MAX97001 audio subsystem devices are designed for maximum efficiency. The high-efficiency 700mW (MAX97001) / 725mW (MAX97000) Class D speaker amplifier operates directly from the battery and consumes no more than 1µA in shutdown mode. The Class H headphone amplifier of the Maxim Integrated MAX97000 / MAX97001 utilizes a dual-mode charge pump to maximize efficiency while outputting a ground-referenced signal that does not require output coupling capacitors. The speaker amplifier incorporates a distortion limiter to automatically reduce the volume level when excessive clipping occurs. This allows high gain for low-levels signals without compromising the quality of large signals.