Low Jitter and Wide Range VCO for CD/DVD/Blu-ray Disc

A voltage-controlled oscillator (VCO) for optical-disc-drive (ODD) applications was developed. This VCO selects the most appropriate current-controlled oscillator (CCO) from three CCOs in order to satisfy various ODD read/write speeds. It produces the frequency characteristics of a maximum frequency limiter in order to prevent unlocking of a PLL. Moreover, the VCO applies a trimming method to correct degradation of frequency characteristics due to process variation. A post-layout simulation of the VCO performance, using the TSMC 90-nm CMOS process, was performed, and the simulation results show that the VCO satisfies each of the 52X-CD, 16X-DVD, and 12X-BD frequency specifications with jitter less than 2%