AS3415 Datasheet, PDF (1/102 Pages) ams AG – Integrated Active Noise Cancelling Solution with Bypass Feature

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 implemented with cheap
resistors and capacitors for lowest system costs.
Ordering Information and Content Guide appear at end of
datasheet.
Key Benefits & Features
The benefits and features of AS3415/35, Integrated Active Noise
Cancelling Solution with Bypass Feature are listed below:
Features
Feed Forward, Feed Back and Hybrid
Integrated depletion mode transistors
Ultra flexible low power EQ circuit
ams Datasheet, Confidential: 2014-Jun-13 [v1-30]
AS3415/AS3435 – 1