3W/channel Class D audio amplifier

February 13, 2014 // By Graham Prophet
Integrating a 32-step up/down volume control, the PAM8407 Class D audio amplifier from Diodes Inc. enables a reduction in component count in a variety of stereo speaker applications, including PCs, docking stations and wireless speakers.

Able to drive dual 4Ω speakers at 3W per channel, from a 5V supply, the amplifier provides designers with simple two key up/down volume control and high-quality sound reproduction. With its fully differential inputs, the device offers low noise, high PSRR and good THD+N performance.

The Class D amplifier’s filter-less output architecture also saves space by minimising the number of external components, while also ensuring a lower quiescent current and improved EMI performance.

With its low pin count SO-16 packaging, small external circuit requirement and an efficiency of 87%, the PAM8407 is appropriate for portable applications. The wide operating voltage range of 2.5V and 6V suits it to a 4x alkaline cell configuration.

The amplifier incorporates a range of safeguards to protect it from damage. These include auto-recovery short-circuit protection, under-voltage lockout and over-temperature protection. It costs $0.18 (100k).

Diodes; www.diodes.com