采用电容延时和反馈的抑制毛刺复位接口电路

Reset IO Circuit with Spike-rejection Using Capacitor Delay and Feedback

针对手机用TFT-LCD驱动控制芯片的应用环境具有高噪声、毛刺持续时间长的特点,提出一种采用电容充放电延时和反馈技术的抑制毛刺复位接口电路。该电路可以消除持续时间长达数微秒的单个毛刺。另外,通过自动选择不同的充放电路径,可实现不同的延迟时间,从而可以消除毛刺的累积效益。设计的复位接口电路已经成功应用于176RGB×220分辨率、26万色手机用TFT-LCD驱动控制芯片。采用0.18μmCMOS中压工艺的HSPICE仿真以及工程样片流片结果表明,所设计的复位接口电路的性能完全满足TFT-LCD驱动控制芯片的复杂应用环境要求,并且具有面积开销较小的特点。

In order to eliminate the effects of high level and long term spikes on TFT-LCD driver IC used for mobile phone, this paper presents a novel spike-rejection reset IO circuit using capacitor charge/discharge delay time and feedback technologies. The proposed circuit can reject the single spike with a width of microsecond level. Furthermore, the capacitor delay circuit can realize different delay times, and therefore can eliminate the spike accumulation effects. The des- igned reset IO circuit is successfully applied in a one-chip TFT-LCD driver IC for 176RGB X 220 resolution, 260 k color panel used for mobile phone. Both the circuit simulation and an engineer- ing sample chip using 0.18μm CMOS middle-voltage process demonstrate that the proposed circuit can meet the specification and performance requirement for TFT-LCD driver IC very well, and it costs less chip size.