AS3415/AS3435 Integrated Active Noise Cancelling Solution with Bypass Feature The AS3415/35 are speaker drivers with Ambient Noise General Description 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 implemented with cheap resistors and capacitors for lowest system costs. Key Benefits & Features The benefits and features of AS3415/35, Integrated Active Noise Cancelling Solution with Bypass Feature are listed below: Figure 1: Added Value of Using AS3415/35 Benefits Features All ANC Topologies Feed Forward, Feed Back and Hybrid No mechanical audio bypass switch Integrated depletion mode transistors Music EQ functionality Ultra flexible low power EQ circuit Longest play time 10mW 1.5V stereo ANC <1A quiescent Highest audio quality 2x24mW, 0.1% THD+N 32, 1.5V supply ams Datasheet, Confidential: 2013-Sep 1-10 AS3415/AS3435 1 Downloaded from DatasheetLib.com - datasheet search engine G e n e ral D e sc rip t ion Benefits Features Two different packages available: Smallest package AS3415 QFN32 5x5mm 0.5mm pitch AS3435 QFN36 5x5mm 0.4mm pitch Low battery indication LED driver with selectable driving strength Different control interface options Push Button-, Slide switch- or IC control interface Highly innovative production trimming interface OTP production trimming via audio interface Active hearing mode with or without ANC and Monitor mode function optional voice EQ Applications The devices are ideal for: Ear pieces Headsets Hands-Free Kits Mobile Phones Voice Communicating Devices Block Diagram The functional blocks of AS3415/35 for reference are shown below: Figure 2: AS3415 Block Diagram AS3415 Block Diagram: This figure shows the block diagram of the AS3415 with all relevant system components. AS3415/AS3435 2 ams Datasheet, Confidential: 2013-Sep 1-10 Downloaded from DatasheetLib.com - datasheet search engine