An Analysis and Design Methodology of Resistor-Based Phase Error Averaging for Multiphase Generation

Abstract

This paper presents a quantitative analysis and design methodology of resistor based phase error averaging scheme for precise multiphase generation Unlike the previously reported works stating that more averaging simply achieves better linearity the proposed analysis leads to the existence of the optimum number of averaging contributions by in eluding the effect of the signal transition time The developed model shows a good agreement with a Monte Carlo circuit simulation A test PLL with a 32 phase two dimensional wig VCO implemented in a 0 18 mu m CMOS generates monotonous 32 phases with the best linearity performance show mg an INL of +027/-1 0 LSB and a DNL of +0 37/-0 27 LSB at 1 2 GHz and an INL of +0 23/-1 57 LSB and a DNL of +044/-044 LSB at I 6 GHz