the portable hearing aid

Published:2011/8/23 23:47:00 Author:Ariel Wang | Keyword: portable, hearing aid | From:SeekIC

The capacitor C3 is used to weaken the high frequency in earphone BE.C4 is the power supply filter capacitor.RP is the potentiometer for volume control.The audio signal from the microphone BM is multi amplified by the hearing aid application specific integrated circuit TB5318.Then it drives the earphone BE to play.As the in-circuit IC1's gain is high,you should pay attention to the layout and routing of the whole machine component.It is to avoid self-excitation.The value selection of the resistance R's pin② of IC1 has something to do with the integrated circuit Sub-block value.You should select it within the range of 360kΩ～1MΩ.BE should adopt high-resistance earphone.



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