1、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 SB32
2、31 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 SB3231s adaptive feedback reduction algorithm provides added stabl
3、e 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-cardio
4、d 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 bi
5、quad 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 t
6、o avoid cloning and software piracy. Software SupportARK 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 :FrontWa
7、ve DirectionalityAdaptive noise reduction Adaptive feedback cancellationWDRC compression with choice of 1, 2 or 4 channels of compressionAuto telecoil with programmable delayEVOKE Lite acoustic indicators Noise generator for tinnitus treatment or in-situ audiometryFrequency response shaping with gra
8、phic EQTrimmer compatibility - four three-terminal trimmers with configurable assignments of control parametersIC and SDA programmingRocker switch support for memory change and/or volume control adjustmentAnalog or digital volume control with programmable rangeHigh quality 20-bit audio processingHig
9、h power/high gain capabilitySOUNDFIT fitting softwareConfigurable low battery indicator8 biquadratic filters16 kHz or 8 kHz bandwidth4 fully configurable memories with audible memory change indicator96 dB input dynamic range with HRX Headroom Extension128-bit fingerprint security system and other se
10、curity features to protect against device cloning and software piracyHigh fidelity audio CODECSoft acoustic fade between memory changesDrives zero-bias two-terminal receiversE1 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
11、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 spe
12、cifications.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 t
13、his 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 desi
14、gn and assembly of a hearing aid:1. Specify the requirements of the product which include the desired features and performance2. Identify the components that will meet the requirements of the design3. Create the mechanical drawings, schematics, and bill of materials for the design4. Build a prototyp
15、e model using the selected components5. Model the acoustic performance of the device to determine the overall acoustic response6. Program the device with the desired configuration7. Calibrate the final assembly8. Regulatory requirements for hearing instruments vary by country and region. Once the de
16、vice 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 WDR
17、C 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 Poweron Delay Battery compartment Ear hook Disposable battery: Size 13 Programmable acoustic tone for low battery voltage Housing available in different colors RoHS compliantBTE 1.0 助听器参考设计主要指标 :图 8.BTE 助听器电路框图
