Wolfson announces two new audio amplifiers

The WM9090 and the WM9010 are the two latest additions to Wolfson’s world-leading audio amplifier portfolio, and will feature in a range of the world’s most highly integrated mobile phones.

Both devices provide exceptional Wolfson-quality audio and extremely low power consumption for optimal audio playback time thanks to highly efficient headphone and speaker drivers. Both devices are packaged in tiny CSP packages, resulting in an ultra small PCB footprint and require minimal external components to reduce bill of materials (BOM) cost.

The WM9090 is an audio subsystem IC and features a mono Class D speaker driver, Class G capless headphone amplifier, Automatic Gain Control and two pairs of differential analogue inputs, all delivered in a small 20-ball 2.5 x 2.0 mm CSP package.

The WM9090’s on-chip mono Class D speaker amplifier provides exceptional audio quality, delivering 750mW into an 80hm speaker at less than 1% THD+N, when powered by a 3.7V battery supply. Wolfson’s new Automatic Gain Control circuit enhances the loudspeaker-mode playback experience by preventing signal clipping and limiting speaker distortion, while maximising the available speaker output power.

Programmable distortion limits allow the system designer to trade off distortion levels versus output power, while an integrated clip detector protects the speaker from being over driven: a common cause of audible distortion and speaker damage.

Additional multimedia phone use cases such as FM radio and MP3 playback are easily incorporated as the WM9090’s analogue input pins are connected to an extensive array of on-chip analogue mixers, enabling system designers to mix any combination of inputs to any output, with full gain control on every signal path.

The audio experience is further enhanced by a sub 1mV DC offset at the headphone outputs for minimal pops and clicks during power up and down sequences. This can be achieved with the minimal of software engineering effort through a single register write for configuring headphone modes.

For the WM9090, PCB space and BOM costs are kept to a minimum as the ultra low power capless Class G headphone amplifier does not require DC blocking capacitors on the output pins. A total PCB footprint, including external passive components, of less than 13 mm sq ensures that the WM9090 consumes a small footprint in space-constrained mobile applications.

Available in a tiny 12-ball 1.8 x 1.3 mm CSP package, the WM9010 is a highly efficient Class G capless headphone amplifier, which is powered from a single 1.8V supply and offers substantially longer playback time over many other Class G headphone amplifiers. This is due to its exceptionally low quiescent power consumption and an input signal envelope detector, which enhances efficiency by tracking the signal level and dynamically adjusting the headphone amplifier power supply circuitry.

The listening experience and system noise performance is also improved through a dedicated feedback pin which removes ground plane noise which can be transmitted to the headphone outputs from flexible connectors, video jacks and noisy ground currents.

David Brown, Audio Amplifiers Product Line Manager at Wolfson Microelectronics commented: “We are delighted that the benefits of the WM9090 and the WM9010 are being recognised by some of the world’s leading mobile phone manufacturers, and that millions of consumers will experience the latest Wolfson-quality audio.

“Combining world-leading audio performance and low power consumption in ultra small packages, the WM9090 and WM9010 represent ideal solutions for the world’s mobile consumer products.”