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AR e c o nfigurable 40-to-67 dB SNR, 50-to-6400 Hz Frame-Rate, Column-Parallel Readout IC for Capacitive Touch-Screen Panels Jun-Eun Park, Student Member , IEEE, Dong-Hyuk Lim
一款可配置SNR和帧率的电容式触摸屏读IC，具有高抗噪性和触摸灵敏度。
40-to-67 dB SNR, 50-to-6400 Hz frame rate, 6.26 mW power consumption
电容式触摸屏抗噪性锁存感应差分感应可配置ADC
▸创新点1：采用锁存感应架构提高抗噪性（系统创新）。通过锁存感应架构有效抑制严重噪声干扰，结合TSP和电荷放大器的带通滤波效应，进一步提升了系统的抗噪性能。
▸创新点2：差分感应方案增强触摸灵敏度（电路创新）。采用差分感应方案不仅提高了触摸灵敏度，还能有效抑制共模噪声，确保在复杂环境中仍能准确检测触摸信号。
▸创新点3：可配置ADC实现SNR和帧率调节（系统创新）。通过调整ADC的可配置分辨率，实现了SNR从40 dB到67 dB的灵活调节，帧率则从50 Hz到6.4 kHz反向缩放，满足不同应用场景需求。
▸创新点4：多采样和平均效应增强抗噪性（电路创新）。利用ADC的多采样和平均效应，进一步提升了系统的噪声免疫能力，确保在高噪声环境下仍能保持稳定的信号检测。
Abstract
This paper describes a capacitive touch-screen panel (TSP) readout IC that provides a recon figurable SNR and frame rate with high noise immunity and touch sensitivity. The readout IC mitigates severe noise interference with a lock-in sensing architecture. In addition, a band-pass filtering effect by the TSP and charge ampli fier further improves the noise immunity. A differential sensing scheme is employed to enhance the touch sensitivity and to reject a commo n-mode noise. A column-parallel incremental ΣΔ ADC is adopted to provide a high resolution and frame rate. Furthermore, a multiple sampling and averaging effect of the ADC enhances the n oise immunity. The readout IC reconfigures its SNR and frame rate by adjusting the con figurable resolution of the employed ADC. The test chip is fabricated in a 0.18 µm CMOS process and occupies a 2.2 mm 2 active area. The test chip achieves a 60 dB SNR and 200 Hz frame rate with a 12×8 T S P .T h eS N Rc a nb ea d j u s t e df r o m4 0d Bt o6 7d B ,w h i l et h e frame rate is then inversely scaled from 50 Hz to 6.4 kHz. The test chip supports a supply voltage range from 2.1 V to 3.3 V and consumes 6.26 mW from a 3.3 V supply.