面向CMUT换能器的驱动电路设计与优化  

Design and Optimization of Drive Circuit for CMUT Transducers

作　　者：沈姝君 何常德[1] 张彦军[1] 张国军[1] SHEN Shujun;HE Changde;ZHANG Yanjun;ZHANG Guojun(State Key Laboratory of Dynamic Testing Technology,North University of China,Taiyuan 030051)

机构地区：[1]中北大学省部共建动态测试技术国家重点实验室,太原030051

出　　处：《舰船电子工程》2024年第6期148-154,共7页Ship Electronic Engineering

基　　金：国家重大科研仪器研制项目(编号:61927807);山西省“1331工程”重点学科建设计划资助项目(编号:1331KSC);国家自然科学基金项目(编号:62075199)资助。

摘　　要：电容式微机械超声换能器(CMUT)具有良好的电声特性、体积小、容易制作阵列等优势,在医学和船舶领域具有广泛的应用前景。论文针对自主研制的一种密排结构CMUT超声换能器的驱动需求,设计了基于FPGA和以MAX14808芯片为核心的驱动电路。用该电路产生方波脉冲,在单端时钟、差分时钟、透明模式下进行了相差角、延迟时间、CMUT收发测试,比较了优缺点。测试结果表明,驱动电路的输出与INP1/INN1输入之间的相差角一致、单端和差分时钟模式下输出与INP1/INN1输入之间的延迟时间差距较小。收发测试时,接收信号随着距离的增加呈指数型衰减,随着输入电压的增加基本呈线性增加且有较小弧度,单端时钟模式的稳定性最好。驱动电路的时钟模式设计,能够重新同步主控芯片的所有数据输入,以减少与FPGA输出信号相关的相位噪声。论文为水下和医疗的超声成像系统提供了硬件支持,为CMUT测试研究提供方法。Capacitive micromechanical ultrasonic transducers(CMUT)have advantages such as good electro-acoustic charac-teristics,small size,and easy fabrication of arrays.It has broad application prospect in the fields of medical science and ships.This paper designs a driving circuit based on FPGA and MAX14808 chip as the core for a self-developed close-packed CMUT element.This circuit is used to generate square wave pulses and perform related tests in the mode of single ended clock,differential clock,and transparent.The test results show that phase difference angle between the output of driving circuit and the INP1/INN1 input is consistent,and the delay time difference between the output and the INP1/INN1 input is small in the mode of single ended clock and differential clock.During transmit-receive test,the received signal decays exponentially with increasing distance,and as the in-put voltage increases it basically increases linearly and has a small arc.The stability of single ended clock mode is the best.The clock mode design of driver circuit can resynchronize all data inputs of the master chip to reduce phase noise related to FPGA output signals.This paper provides hardware support for underwater and medical ultrasound imaging systems,also provides methods for CMUT testing research.

关 键 词：电容式微机械超声换能器 驱动电路 超声成像系统 时钟模式 透明模式 

分 类 号：TN791[电子电信—电路与系统] TB552[理学—物理]