中圖分類號(hào)：TN432 文獻(xiàn)標(biāo)志碼：A DOI: 10.16157/j.issn.0258-7998.223029 中文引用格式： 曹楊，曹振吉，曹靚，等. 一種片外電容交叉充放電型振蕩電路設(shè)計(jì)[J]. 電子技術(shù)應(yīng)用，2023，49(3)：77-81. 英文引用格式： Cao Yang，Cao Zhenji，Cao Liang，et al. An oscillator circuit with cross charge and discharge by off-chip capacitors[J]. Application of Electronic Technique，2023，49(3)：77-81.
An oscillator circuit with cross charge and discharge by off-chip capacitors
Cao Yang，Cao Zhenji，Cao Liang，Zhao Guilin
(The 58th Research Institute， China Electronics Technology Group Corp.， Wuxi 214035， China)
Abstract： CMOS Ring Oscillator has many advantages such as small layout area, large frequency range and easy integration. It is widely used in the DC-DC buck converter and electronic communication systems. On the basis of the traditional ring oscillator circuit, an independent charge and discharge control path is designed to realize a cross charge and discharge ring oscillator circuit, and a lower frequency oscillation period is obtained by externally connecting an off-chip capacitor. Based on 0.18 μm process, the circuit has been simulated with HSIM tool. After the back-end physical implementation, the layout of the oscillation occupies an area of 172 μm×76 μm. Using tools to extract parasitic parameters from the layout and conduct post-simulation, the simulation results indicates that with externally connecting an off-chip capacitor, and the power supply voltage in 3.3 V and temperature in 25℃, the oscillator has a clock period of 1.2 ms. With the power supply voltage changes in 2.7 V~5.5 V and temperature changes in -55℃~125℃, the frequency deviation is 5.83%.The circuit has been successfully applied in a power management chip.
Key words : ring oscillator；charge and discharge of capacitor；power management chip；clock
