Wolfson Microelectronics’ new single-chip, monophonic WM9081 DAC and speaker amplifier deliver optimum sound-pressure levels and maximum intelligibility from low-cost speakers, such as those in portable navigation devices, mobile handsets, digital radios, and conference speakerphones. The IC has a high-efficiency, 2.6W speaker amplifier that can operate in either Class AB or Class D, a dynamic-range controller, and a five-band ReTune Mobile parametric equalizer. SNR (signal-to-noise ratio) is 92 dB in Class D mode, and THD+N (total harmonic distortion plus noise) is 1% at 2.4W output power into a 4Ω speaker load. The 9081 uses 30% less board area and costs 20% less in bill-of-materials expenses than a two-chip approach.

The integrated ReTune Mobile equalizer has fully programmable coefficients, allowing the user to define speaker-frequency-response compensation and music profiles. Programmable dynamic-range control boosts low-level signals to maximize volume for improved intelligibility. The chip comes in a 28-pin COL QFN package; an evaluation system includes a board, schematics, a Linux driver, and a downloadable software GUI (graphical user interface), which allows the developer to modify an interactive version of the register map in real time and modify the device configuration while developing software settings.