Mono DAC Integrates Amplifier For Small Speakers

The WM9081 is a single-chip mono digital-to-analog converter (DAC) and speaker amplifier particularly suited for delivering optimum sound pressure levels and maximum intelligibility from low-cost speakers. The device integrates a high-efficiency 2.6-W switchable class AB/D amplifier, a dynamic range controller, and the ReTune Mobile five-band parametric equalizer. Signal-to-noise ratio in class D mode is 92 dB, and total harmonic distortion plus noise is 1% at 2.4 W into 4-O speakers. Compared to typical two-chip solutions that use a DAC and separate class D amplifier, the WM9081 uses about 30% less board space and reduces BOM cost by an average of 20%. The ReTune Mobile five-band parametric equalizer with fully programmable coefficients allows end users to define speaker frequency response compensation and music profiles. The device supports four control interface addresses and four-channel TDM to allow multiple devices to be configured and driven independently. Control of the IC is through a standard two-, three-, or four-wire control interface or by hardware control pins. The WM9081 is sampling now in a 28-pin COL QFN package. Price is $0.80 in volumes of 1000. WOLFSON MICROELECTRONICS PLC, Edinburgh, UK. +44 (0) 131 272 7000.