摘要
针对传统电容式触摸芯片的采样信号易受外部噪声干扰而引发注入锁定的现象,设计了一种多频采样电路。该电路引入5条充电电流支路,实现多频采样功能,减小采样信号受注入锁定现象的影响,提高采样精度。同时,设计了一种DOM(Delta over the Mean)算法对采样信号进行处理,以此监测触摸输入引脚的电容值变化。仿真结果表明,多频采样电路输出的采样信号受噪声干扰的计数值偏差仅为0.46%;FPGA验证表明DOM算法的计算精度为1×10^(-8),最大绝对误差不超过0.4%;该电路具有强抗干扰、高可靠性、高精度特性,可应用于各类电容式触摸芯片。
To address the issue of injection locking caused by external noise interference in traditional capacitive touch chips,a multi-frequency sampling circuit is designed.This circuit introduces five charging current branches to achieve multi-frequency sampling,thereby reducing the impact of injection locking on the sampling signal and improving sampling accuracy.Additionally,a Delta over the Mean(DOM)algorithm is proposed to process the sampled signal and monitor capacitance variations at the touch input pin.Simulations show that the deviation of the sampled signal count under noise interference is only 0.46%.FPGA verification demonstrates that the DOM algorithm achieves a calculation accuracy of 1×10^(-8),with a maximum absolute error of no more than 0.4%.The proposed circuit exhibits strong anti-interference capability,high reliability,and high precision,making it suitable for various capacitive touch chips.
作者
谢海情
黄吕梁
许彬
赵欣领
谌运政
XIE Haiqing;HUANG Lvliang;XU Bin;ZHAO Xinling;CHEN Yunzheng(School of Physics and Electronic Science,Changsha University of Science and Technology,Changsha 410114,China;Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering,Changsha University of Science&Technology,Changsha 410114,China)
出处
《电子设计工程》
2026年第4期43-47,共5页
Electronic Design Engineering
基金
湖南省自然科学基金资助项目(2024JJ7610)
湖南省教育厅科学研究项目(24A0227)
长沙理工大学实践创新与创业能力提升计划项目(CLSJCX23111)
长沙理工大学研究生科研创新项目(CSLGCX23111)
国家级大学生创新创业训练计划项目(202210536038)。
关键词
多频采样
电容式触摸
触摸检测
差分结构
注入锁定
multi-frequency sampling
capacitive touch
touch detection
differential structure
injection locking
