← 返回 JSSC 论文列表JSSC 2019第5期Other0.18-μm CMOS
A Noise-Immunity-Enhanced Analog Front-End for Touch-Screen Controllers With 20-
设计了一种具有高抗噪能力的触摸屏控制器模拟前端,采用多通道驱动和噪声过滤接收结构。
54-dB SNR, 120-Hz帧率, 20-V PP噪声抗扰度
模拟前端触摸屏控制器抗噪能力多通道驱动噪声过滤
▸创新点1:多通道驱动(MCD)TX方案采用低偏移正交序列调制触摸屏面板的互电容,结合跳频技术分散噪声干扰,显著提升噪声抑制能力(20-V PP噪声容限)。该方法通过序列优化和动态频率调整实现系统级抗干扰创新。
▸创新点2:噪声过滤RX结构通过预滤波差分传感方法增强触摸灵敏度并抑制共模噪声。其核心在于前端模拟信号处理电路的拓扑优化,结合高线性度设计实现54dB SNR的电路级性能突破。
▸创新点3:RX调制方案通过下变频电容信号和多路复用后续模块,实现高效高阶噪声过滤。该混合信号处理架构创新性地将模拟域调制与数字域滤波结合,支持120Hz帧率可扩展性。
▸创新点4:增量式模数转换器采用自适应量化策略,在0.18μm CMOS工艺下实现36×64触摸屏的高分辨率检测(94.5mW@3.3V),属于低功耗电路设计创新。
Abstract
This paper describes the design of an analog front-
end (AFE) for capacitive touch-screen controllers that provide
highly enhanced noise immunity. The proposed AFE mitigates
severe noise interference using a multi-channel-driving (MCD)
TX scheme and a noise-filtering RX structure. The MCD scheme
with a frequency hopping technique modulates mutual capaci-
tances in a touch-screen panel (TSP) using low-offset orthogonal
sequences, spreading the noise interference. In the RX sensing
block, a pre-filt