一种频率可调CMOS环形振荡器的分析与设计

给出了一个采用0．6um CMOS工艺设计的改进结构环形振荡器，电路由RC充放电回路、施密特单元以及反相延时单元组成，结构简单，工作频率受集成电路工艺参数影响小。该电路带有使能控制端，并且通过调节少量的外部元件可以改变电路的振荡频率，适用作各类中／低频数字集成电路中的时钟产生电路。分析了改进结构环形振荡器的工作原理，给出了Hspice软件环境下电路仿真方法。电路流片封装后的实际测试结果表明，用该结构的环形振荡器作为时钟产生电路，工作稳定，满足了系统工作要求。

Design of a Novel Ring Oscillator with Tunable Frequency Range

A novel ring oscillator realized in 0. 6um CMOS process is presented. This simple circuit includes a RC charge/discharge cell, Schmitt cell and several inverter cells, the frequency of this oscillator is insusceptible to integrated circuit technology. It can be used as a clock generator for low or intermediate frequency circuits with tunable frequency range. After the discussion of the circuit, the skill about how to simulate the circuit in Hspice software is introduced. Finally, the circuit is manufactured and packaged, the measured results shows that the novel ring oscillator meets the need of the system application.