Research On Integrated SOI CMOS Ring VCO

With the rapid development of communication and electronic field, VCO(Voltage Controlled Oscillator) becomes more and more important in electronic system. Integrated ring VCO can easily achieve relatively wide frequency tuning range, it occupys a small chip area and easy to be realized through process. It is widely used in systems of wireless and wired transceiver, data communication, clock recovery and many other systems to select frequency, filter wave, tune frequency or to provide precise and stable cycle clock signal. The main development tendency of VCO is wide tuning range, good tuning linearity and low phase noise. The design of high performance VCO with proprietary intellectual property rights is of great significance to the development of the electronic information industry of our country.The demand of low power disspation, high density, superspeed, thermostability etc. was put forward by high performance electronic products, which pushed forward the continuous improvement of the level of integrated circuit technology. Taking into consideration of the physical limit, troditional silicon CMOS process has difficulty in satisfying the harsh requirement of high performance. SOI(Silicon-On-Insulator) technology is recognized as "New Genaration Silicon Integrated Circuit technology" all over the world. It has extremely extensive application fields and very good development prospects. If silicon CMOS circuit is transplanted on SOI substrate, it will have features of thermostability, low power disspation, anti-radiation and so on. SOI technology has been widely used overseas, but at home most of the SOI research are only at circuit experiment stage and not as mature as silicon CMOS technology.The development history of VCO was reviewed, the working principle of VCO was analysed. Then the main performance index of VCO was introduced, especially phase noise was discussed in details. After that, the frequency tuning way of ring VCO was analysed, single-ended and difference ring VCO was discussed respectively, a differential ring VCO circuit was designed and its functional simulation and performance optimization was made referring to CSMC0.5μm CMOS process. Then the mask layout was designed and drawn, and post simulation was made furthermore. The post-simulation results show that the frequency tuning range is7.139-147.3MHz, the phase noise at center frequency is-123.4dBc/Hz@1MHZ、-101.4dBc/Hz@100kHz, power dissipation is5.27mW, the waveform is smooth, and the oscillation amplitude is relatively large. SOI CMOS process was introduced, the SOI mask layout of the differential ring VCO was drawn according to the design rule of0.5μm SOI CMOS process. The oscillator can be used in circuits of clock generator, timer/counter, data clock recovery and so on.