A low-power adaptive bandwidth PLL and clock buffer with supply-noise compensation

This paper describes a fully integrated low-jitter CMOS phase-locked loop and clock buffer for low-power digital systems with a wide range of operating frequencies. The design uses static CMOS inverters as a building block of the voltage-controlled oscillator and clock buffering. To reduce supply-induced jitter, programmable circuits with opposite sensitivity compensate for the delay variations. Both elements have supply-induced delay sensitivity of less than or equal to 0.1% - delay/1% - V-DD. The design is fabricated in C25-mum CMOS technology and consumes 10 mW from a 2.5-V supply. The experimental results verify that the proposed methods significantly improve the jitter.