Noise and Jitter Transfer Characteristics of an On-chip Voltage Reference-Locked Loop

The noise and jitter characteristics of an on-chip voltage reference-locked ring oscillator are presented. The frequency of the ring oscillator, 683 MHz, was locked to the on-chip voltage reference by means of a frequency-to-voltage converter and the noise and jitter transfer characteristics of this loop were derived, including the noises of the reference voltage and ring oscillator. Simulations were performed to see the effects of different noise types (white and 1/f noise) on the cumulative jitter of the locked ring oscillator. Finally, these results were verified by jitter measurements performed using an integrated time-to-digital converter (TDC) fabricated on the same die (0.18 ¿m CMOS process).