The WM8993 is the first in a whole new family of next generation audio hubs, combining Wolfson's market leading flexible hub architecture and ultra low power technology. It enables users to listen to Wolfson's Pure Sound for 10-12 hrs on an intercontinental flight, then land and start making calls, comments Darren Hobbs, Audio Hub Product Line Manager at Wolfson. The WM8993 offers best in class audio performance, dramatically extended playback time and a highly flexible audio mixing experience for today's demanding multimedia smart phones, all at the lowest possible total BOM. With the WM8993, you really get the best performance and the longest battery life from your multimedia mobile phone, at the lowest system cost and quickest time to market.
The WM8993 hub manages all audio processing and routing in a multimedia mobile handset, enabling it to support a wide range of audio architectures and usage scenarios. By managing, converting and processing the full array of diverse audio streams, including voice, speaker, microphone, music and headphone signals, the WM8993 is able to provide the flexible audio mixing capability and performance increasingly expected of today's portable multimedia applications.
The WM8993 integrates Wolfson's flexible ReTune Mobile Parametric Equaliser for the optimisation of speaker characteristics and improved speaker frequency response. Programmable dynamic range control is also integrated to help boost low-level signals and optimise dynamic range for the challenging mobile environment. This helps maximise volume for the improved audibility of ringtones and enhanced music playback on handsets' small, low cost speakers. Dynamic range control also helps prevent audio signal clipping and distortion, which can overload the battery, cause premature shutdown due to battery droop and potentially damage the speakers.
Ground referenced Class W headphone drivers enable the WM8993 to deliver improved bass response and achieve total CODEC power consumption typically below 5mW, which equates to 100 hours of playback on a single charge (when used with the latest processors). The WM8993's integrated charge pump removes the need for costly DC-blocking capacitors and enables significant savings in PCB space and the audio subsystem bill of materials (BOM). Active ground loop noise rejection and DC offset correction help prevent pops & clicks and ground noise from degrading headphone output quality.
For added flexibility the WM8993's high power speaker drivers operate in Class D or AB mode. In 1W stereo mode the device drives an 8Ω BTL speaker load at <1% THD whilst in 2W mono mode, the speaker drivers can be connected together to drive a 4Ω load for extra power output. Low leakage and a high power supply rejection ratio (PSRR) across the audio band also enable direct battery connection for the speaker supply.
The WM8993's fully differential internal architecture and on-chip RF noise filters ensure a very high degree of noise immunity whilst Wolfson's next generation FLL helps to reduce system power and increase flexibility. A highly flexible input configuration also supports multiple microphone or line inputs (mono or stereo, single-ended or differential).