AS3415

General Description Figure 1: Added Value of Using AS3415/35 Benefits All ANC Topologies No mechanical audio bypass switch Music EQ functionality AS3415/AS3435 Integrated Active Noise Cancelling Solution with Bypass Feature The AS3415/35 are speaker drivers with Ambient Noise Cancelling function for headsets, headphones or ear pieces. They are intended to improve quality of e.g. music listening, a phone conversation etc. by reducing background ambient noise. The fully analog implementation allows the lowest power consumption, lowest system BOM cost and most natural received voice enhancement otherwise difficult to achieve with DSP implementations. The device is designed to be easily applied to existing architectures. An internal OTP-ROM can be optionally used to store the microphones gain calibration settings. The AS3415/35 can be used in different configurations for best trade-off of noise cancellation, required filtering functions and mechanical designs. The simpler feed-forward topology is used to effectively reduce frequencies typically up to 2-3 kHz. The feed-back topology with either 1 or 2 filtering stages has its strengths especially at very low frequencies. The typical bandwidth for a feed-back system is from 20Hz up to 1 kHz which is lower than the feed-forward systems. The filter loop for both systems is determined by measurements, for each specific headset individually, and depends very much on mechanical designs. The gain and phase compensation filter network is...