雙耳助聽器之2Mbps人體通道傳收器設計與實現

Abstract

我們使用人體當訊號通道，並設計低功率的晶片達成助聽器雙耳通訊的目的。我們利用4個銀片電極採取波導方式來連接人體，傳輸端和接收端各有兩個電極，把訊號從一耳傳到另一耳。這顆晶片包含了傳送端和接收端。傳送端能對資料進行編碼，並轉成每秒兩百萬個位元、峰對峰值一伏特的方波打入電極，接收端包括類比前端、全數位的資料回復電路，以及解碼器。類比前端可以把經過通道的小訊號還原成數位訊號。全數位資料回復器可以回復資料的時間性，解碼器則把經過編碼的資料解碼。晶片採用台積電65奈米製程。在數位電源為0.5伏特，類比電源為1伏特，且傳輸速率為每秒兩百萬位元的情況下，實際量測功率耗損只有80微瓦。第二版在與第一版相同的電源下，數位架構相同，並改進了類比前端的功耗，模擬結果顯示平均功率耗損只有56.48微瓦。我們還發展出一套適用在人體通道的助聽器雛形系統，傳送語音訊號並播放出聲音，雛形系統的結果用嵌入式的邏輯分析儀驗證。

We use a body channel and a low-power transceiver design to achieve binaural communication for hearing aids. Transmitter and receiver use two Ag electrodes, respectively, to the body channel with the waveguide type. The transmitter encodes and transmits data of 2-Mb/s and 1-V peak-to-peak square waveform to the electrodes. The receiver includes an analog front end (AFE), an all-digital data recovery circuit and a decoder. This chip is implemented with a TSMC 65-nm CMOS process using 0.5-V supply in the digital transceiver and 1-V supply in the AFE. When working at 2 Mb/s, the measured power consumption is only 80 uW. The second version uses the same supply voltage and digital architecture with the first version and improves the power consumption of AFE. The power simulation result of the second version circuit is only 56.48 uW. We develop a prototyping system of human body channel for HA. We transmit voice data through the body channel and use the speaker to play sound. The results of the prototype system are verified by embedded logic analyzer.