A current-controlled oscillator coarse-steering acquisition-aid for high frequency SOI CMOS PLL circuits

摘要

A self-adjusting frequency control circuit for a high-speed phase-locked loop (PLL) system is designed for implementation in a 0.25 /spl mu/m SOI CMOS technology. This coarse-steering circuit uses a current sensor to indirectly detect the running frequency of the VCO/ICO and combine the result generated from a simple frequency comparator to determine an active frequency control range for the PLL. The entire circuit has been simulated with a wide frequency range of 850 MHz and a power supply voltage of 1.8 volts on HSPICE.