A 3 V 200 MHz PLL with a low-noise VCO based on a power-efficient low-ripple DC-DC converter

Abstract

This paper describes a phase-locked loop (PLL) clock generator with low sensitivity to power supply noise. A voltage controlled oscillator employing a source follower reduces power supply noise sensitivity with the proposed power-efficient low-ripple DC-DC converter. Simulated clock jitter is less than /spl plusmn/20 ps, with a 200 mV peak-to-peak sinusoidal noise signal of 1 MHz to 400 MHz applied to a power supply. The proposed PLL simulated in a 0.65 /spl mu/m double-poly double-metal CMOS process consumes 27 mW at 200 MHz from a 3 V supply. The prototype is under fabrication.