A Frequency Stabilization Circuit for The Voltage Controlled Ring Oscillator

A design of a frequency stabilization circuit for the voltage controlled ring oscillator that can stabilize the voltage source and compensate the temperature and process variation is presented here. A linear voltage source using bandgap voltage reference and a temperature and process compensated circuit used for adjusting the control voltage are introduced into the oscillator. The simulation results show that when the proposed oscillator is set at 620 MHz, the output frequency has a variation of 0.13% for the voltage source in the range 3.0 V to 3.6 V when the temperature is 27degC and the process corner is typical; the output frequency has a variation of 0.8% for the temperature range of 0degC to 120degC when the voltage source is 3.3 V and the process corner is typical; the output frequency variation changes from 34.3% to 19.1% after the compensation circuit is added for all the process corners when the temperature is 27degC.