Locked ranges of frequency divider based on injection-locked relaxation oscillator

In this article, the principle for determining locked ranges of the frequency divider based on the injection locked relaxation oscillator (ILRO-FD) is proposed. The proposed principle shows that the ILRO has many frequency-division ratios and can indicate that which ratios are suitable for frequency dividers. In addition, based on the proposed principle, it is found that the patterns of frequency-division ratios of ILRO depend on the charge-pump circuit's current ratio. Moreover, the proposed principle is verified by the simulation results of the ILRO-FD based on 0.35um-CMOS technology of TSMC.