Wolfson claims highest performing ultra compact MEMS microphones

These new devices are the first results from Wolfson’s acquisition of Oligon in January 2007 and the first deployment of Wolfson’s AudioPlus™ True Mics technology. Wolfson’s technology is based on its unique MEMS transducer IP which uses standard CMOS foundries to deliver greater reliability, repeatability and scalable production capacity, enabling cost and flexibility benefits to be passed on to the end customer. MEMS microphones can withstand the temperatures used in surface mount reflow soldering techniques and can be used with automated pick and place technology. This removes the need for manual insertion of the microphone and reduces time and cost of assembly.

The compact WM7110 (4.72 x 3.76 x 1.25mm package size) and ultra compact WM7120 (3.76 x 2.95 x 1.10mm package size) devices typically consume 160µA making them ideal for use in portable applications such as mobile phones, portable media players, digital still cameras, video cameras, navigation devices and noise cancelling headphones. Both devices offer an improved 62dB SNR (A-weighted) performance, reducing the noise floor in the microphone to ensure cost effective delivery of crystal clear sound capture. The devices also feature low THD (Total Harmonic Distortion) of just 0.5% maximum at 100dB SPL, excellent linearity and flat phase response.

As the first MEMS silicon microphones to offer a tighter sensitivity tolerance of +/-1dB, the enhanced WM7110E and WM7120E devices change the rules for multiple microphone design and bring innovative new applications into cost effective reach. As well as removing the need for costly production line testing and calibration software algorithms, the tighter +/-1dB sensitivity tolerance give the microphones better matching - a crucial element in the design of microphone arrays for beam-steering. Noise cancellation design can also be substantially improved with closer matched microphones.

Peter Frith, CTO at Wolfson comments, “The new ultra compact True Mics MEMS silicon microphones bring Wolfson quality sound recording to a wide range of consumer applications. Through our proprietary CMOS/MEMS membrane technology and +/-1dB sensitivity tolerance we’re bringing innovative multiple microphone applications into cost effective reach for OEMs/ODMs”

As part of the Wolfson AudioPlus strategy, the new silicon microphones are also fully compatible with all the Company’s other audio products including Wolfson’s Enhanced Soundware active noise cancellation technology. Adding microphones to its portfolio allows Wolfson to offer more components of the audio signal chain.