Date: 28/10/2011

Noise cancellation ICs from AMS deliver 30 dB of noise reduction

austriamicrosystems has added two new AS3400 and AS3420 to its Active Noise Cancelling (ANC) IC family for improved hearing in noisy environments. austriamicrosystems says it is the lowest power available, resulting in 20% longer battery life than other ANC solutions and they improve audio performance over competing solutions with a 10 dB positive SNR -- no matter the environment -- improving intelligibility in wired or wireless mono communication headsets.

austriamicrosystems explains that the Active Noise Canceling IC AS3420 is a fully differential ANC speaker driver IC specifically designed to connect directly to common SoCs for mono Bluetooth applications and other types of wireless headsets. The AS3420 Bluetooth speaker driver can be used in both feed-forward and feedback configurations. The device allows for the development of simple low-order filters as well as complex multiple-order filters, thanks to the integrated low noise amplifiers. The microphone input features a fully differential low-noise amplifier, adjustable gain over 128 steps, and OTP (one time programmable) ROM for factory setting of gain.

austriamicrosystems also explains that the AS3400 is a low-power ANC speaker driver designed to reduce ambient background noise in wired headsets and improve the quality of conversations or listening to music, and it can be configured like the AS3420, for feedback or feed-forward operation. Both receive path ICs deliver up to 30 dB of noise reduction, provide click- and pop-less operation at start-up and during mode switching. They also include low THD (total harmonic distortion) headphone amplifiers -- 0.1% and 0.03% for the AS3420 and AS3400, respectively. Both driver ICs draw just 3.8 mA at 1.5 V and less than 1 µA quiescent current in mono mode.

"How many times do you say 'Could you repeat that please, I didn't quite understand you'", commented Oliver Jones, austriamicrosystems' Marketing Manager for Audio products. "People want to stay in touch, no matter where they are. Active Noise Canceling significantly improves listening quality even in mono applications. Solutions that implement the ANC function digitally via software enhancements require more power and do not achieve the same performance. That approach simply increases the sound volume in loud environments and, under certain conditions, distorts the caller's voice."

austriamicrosystems' AS3400 is housed in a 4 x 4 mm QFN24 package; the ANC IC AS3420 comes in a QFN20 4 x 4 mm package. Both speaker driver ICs operate with a 1.0 to 1.8 V supply and are specified over a -20 to +85°C temperature range.

Price and availability: The ANC ICs AS3400 and AS3420 are available now and are priced at $2.10 and $1.95, respectively, in 1000-piece quantities.
For more information visit http://www.austriamicrosystems.com/audio/ANC