一种高频高精度窗口比较式CMOS振荡器的设计

Design of a Window-Comparator CMOS Oscillator with High Precision and High Frequency

研究并设计了一种用于彩屏手机TFT-LCD驱动控制芯片的高性能内置CMOS振荡电路。该振荡电路采用窗口比较(Window-Comparator)形式,利用以高灵敏度比较器为核心的开关控制电路,并配合恒流源充放电技术,实现了低电压供电、高频高精度的矩形波振荡电路。振荡器的设计振荡频率为500 kHz,采用0.25μm CMOS工艺实现。HSPICE仿真结果表明,振荡频率精度在±1.68%以内。

A high quality built-in CMOS oscillator in TFT-LCD driver IC used for mobile phone is studied and designed. The oscillator is based on window-comparator principle. A couple of comparators with high sensitivity are used as the key element of the switch control circuit, and constant current sources are used for charging and discharging the capacitor. Implemented in 0. 25 btm CMOS process, the oscillator circuit has achieved low power supply voltage, high frequency and high precision. HSPICE simulation results show that the oscillating frequency is influenced little by process, and the error is less than ＋1.68%.