Austriamicrosystems has announced active noise cancelling ICs designed for providing good hearing in Bluetooth and wired mono headsets. The AS3400 and AS3420 ICs feature low power and good audio quality for wired and wireless headsets, respectively. They feature long battery life and offer audio performance with a 10dB positive supernova remnant, says the company.
The AS3420 is designed to connect directly to common SoCs for mono Bluetooth applications. The analogue implementation is claimed to reduce the background noise and can be used in both feed-forward and feedback configurations.
According to the company, the drivers allow for the developnt of simple low-order filters as well as complex multiple-order filters. The microphone input features a differential low-noise amplifier, adjustable gain over 128 steps, and one time programmable ROM for factory setting of gain. Both receive path ICs deliver up to 30dB of noise reduction, provide click- and pop-less operation at start-up and during mode switching. They also feature low total harmonic distortion in headphone amplifiers of 0.1 and 0.03%. The ICs draw 3.8mA at 1.5V and less than 1µA quiescent current in mono mode.
The AS3400 is housed in a 4x4mm QFN24 package and the AS3420 comes in a QFN20 4x4mm package. Both speaker driver ICs operate with a 1.0 to 1.8V supply and are specified over a -20 to +85°C temperature range.
