一种低抖动、宽调节范围的带宽自适应CMOS锁相环

提出了一种低抖动、宽调节范围的带宽自适应CMOS锁相环.由于环路带宽可根据输入频率进行自动调节,电路性能可在整个工作频率范围内得到优化.为了进一步提高电路的抖动特性,在电荷泵电路中采用匹配技术,并在压控振荡器中应用电压-电压转换电路以减小压控振荡器的增益.芯片采用SMIC 0.35μm CMOS工艺加工.测试结果表明该锁相环电路可在200MHz～1.1GHz的输出频率范围内保持良好的抖动性能.

An Adaptive-Bandwidth CMOS PLL with Low Jitter and a Wide Tuning Range

This paper presents a novel adaptive-bandwidth charge pump PLL with low jitter and a wide tuning range. Withan adaptive bandwidth,the proposed PLL can scale its loop dynamics proportional to the output frequency and maintainoptimal performance over its entire output range. In order to improve the jitter performance of the PLL,a matching tech-nique is employed in the charge pump,and a voltage-to-voltage converter is used to achieve a low gain VCO. The experi-mental chip was fabricated in a 0. 35μm CMOS process. The measured results show that the PLL has perfect jitter per-formance within its operating range from 200MHz to 1.1GHz.