A high frequency resolution Digitally-Controlled Oscillator using single-period switching scheme

This paper proposes a high frequency resolution Digitally-Controlled Oscillator (DCO) using single-period control bit switching scheme. The proposed scheme controls the tuning word of DCO in a single period for the fine frequency tuning. The LC type DCO is implemented to realize the proposed scheme, and is fabricated using a standard 65nm CMOS technology. The measurement results show that the implemented DCO improves the frequency resolution from 0.63MHz to 0.27MHz without phase noise degradation with an additional area of 200μm².