1.9W class-D audio amplifier extends battery life

Combining a high-efficiency class-D audio power amplifier and boost converter, the PAM8905 drives up to 1.9W into an 8Ω speaker with a total harmonic distortion plus noise of just 1%. The fully synchronous topology of the boost circuit minimises external components, achieves higher efficiency and maximises the output power of the amplifier compared to a standard amplifier connected directly to the battery.

Aimed at smartphones operating from a single-cell lithium-ion battery, the PAM8905 features DC input voltage protection to prevent damage to the speaker in the event of input voltages with high DC bias levels. The device is also protected against output short circuits with full auto-recovery and features under-voltage lockout and over-temperature protection.

Supplied in a 12-pin U-WLB1520-12 CSP package measuring just 15x20x0.6mm, the PAM8905 provides a low pin-count and small size solution to save board space. The devices are priced at $0.37 each in 10,000 unit quantities.