On-Semi-Rhythm-SB3231-BTE-1.0助听器参考设计

On Semi Rhythm SB3231 BTE 1 0 助听器参考设计 On Semi 公司的 Rhythm SB3231 是可配置的 DSP 系统 具有四路自适应反馈抵消的压缩 电路 自适应降噪和 FrontWave 静态方向性 I2C 和 SDA 编程 模拟或数字音量控制 高质量 200 位音频处理和高保真 CODEC 大功率 高增益功能 16 kHz 或 8 kHz 带宽 本文介绍了 Rhythm SB3231 主要特性 框图 测试电路图 典型可编程和调整应用电路图 以及 BTE 1 0 助听器参考设计主要特性和主要指标 BTE 助听器电路框图和主要元件图 Rhythm SB3231 is a trimmer configurable DSP system based on a four channel compression circuit featuring Adaptive Feedback Cancellation Adaptive Noise Reduction and FrontWave static directionality Based on a phase cancellation method Rhythm SB3231 s adaptive feedback reduction algorithm provides added stable gain to enable extra gain and user comfort It features rapid adjustment for dynamic feedback situations and resistance to tonal inputs The FrontWave directional system utilizes a pair of microphones to create a fully customizable static polar pattern such as bidirectional cardiod hyper cardiod and super cardiod In addition to these adaptive algorithms Rhythm SB3231 also supports the following features up to four channel WDRC low distortion compression limiting cross fading between audio paths for click free memory changes eight band graphic equalizer eight configurable generic biquad filters programming speed enhancements in channel squelch to attenuate microphone and circuit noise in quiet environments optional peak clipping flexible compression adjustments volume control rocker switch noise generation for tinnitus treatment and industry leading security features to avoid cloning and software piracy Software Support ARK is a set of software building blocks that can help reduce the time it takes to develop hearing aid fitting software ARKonline is an efficient web based tool for creating product libraries and keeping them organized Rhythm SB3231 主要特性 FrontWave Directionality Adaptive noise reduction Adaptive feedback cancellation WDRC compression with choice of 1 2 or 4 channels of compression Auto telecoil with programmable delay EVOKE Lite acoustic indicators Noise generator for tinnitus treatment or in situ audiometry Frequency response shaping with graphic EQ Trimmer compatibility four three terminal trimmers with configurable assignments of control parameters I C and SDA programming Rocker switch support for memory change and or volume control adjustment Analog or digital volume control with programmable range High quality 20 bit audio processing High power high gain capability SOUNDFIT fitting software Configurable low battery indicator 8 biquadratic filters 16 kHz or 8 kHz bandwidth 4 fully configurable memories with audible memory change indicator 96 dB input dynamic range with HRX Headroom Extension 128 bit fingerprint security system and other security features to protect against device cloning and software piracy High fidelity audio CODEC Soft acoustic fade between memory changes Drives zero bias two terminal receivers E1 RoHS compliant hybrid 图 1 Rhythm SB3231 框图 图 2 Rhythm SB3231 测试电路图 图 3 Rhythm SB3231 典型可编程应用电路图 图 4 Rhythm SB3231 典型调整应用电路图 BTE 1 0 助听器参考设计 The BTE 1 0 Reference Design is a hardware reference design for a Behind The Ear BTE hearing aid using the Rhythm SB3231 preconfigured DSP system It contains a single SB3231 device which enables implementation of a complete digital hearing aid with state of the art features and specifications This reference design assumes that the BTE will be assembled using point to point wiring of the components Therefore no description of a PCB design is given A flex PCB implementation is a preferred component interconnect method for large production volumes but is beyond the scope of this document The SB3231 design is supported by an extensive collection of design tools and documentation This also details how ON Semiconductor ARK tools are used for the design and configuration of a new hearing aid The following steps outline the basic procedure used in this document for the design and assembly of a hearing aid 1 Specify the requirements of the product which include the desired features and performance 2 Identify the components that will meet the requirements of the design 3 Create the mechanical drawings schematics and bill of materials for the design 4 Build a prototype model using the selected components 5 Model the acoustic performance of the device to determine the overall acoustic response 6 Program the device with the desired configuration 7 Calibrate the final assembly 8 Regulatory requirements for hearing instruments vary by country and region Once the device has been assembled and tested it will be necessary to submit the device for regulatory testing and approval before it can be sold as a hearing instrument 图 5 BTE 1 0 助听器参考设计元件装配图 图 6 BTE 助听器元件图 图 7 BTE 1 0 助听器参考设计主要元件图 BTE 1 0 助听器参考设计主要特性 Programmable BTE instrument with four channels of WDRC compression 96 dB input dynamic range Compatible with SOUNDFIT fitting software Adaptive feedback cancellation Programmable crossover frequencies 4 hearing programs Adaptive noise reduction using dual microphones Noise generator for tinnitus masking Auto telecoil with programmable delay Programmable Volume control VC Pushbutton memory select Power on Delay Battery compartment Ear hook Disposable battery Size 13 Programmable acoustic tone for low battery voltage Housing available in different colors RoHS compliant BTE 1 0 助听器参考设计主要指标 图 8 BTE 助听器电路框图