A low-voltage low-power programmable g(m)-C filter using dynamic gate biasing

This thesis discusses a novel, low-voltage analog circuit technique based on charge pumps called Dynamic Gate Biasing (DGB). The main contributions of this thesis are in three areas: experimental verification of DGB, development and application of a programmable filter methodology using first order perturbations, and theoretical as well as experimental investigation of the voltage ripple resulting from DGB. Overcoming the voltage ripple from the charge pumps used in DGB is necessary in order for the technique to succeed in low-voltage analog applications. A mathematical analysis of the origins of voltage ripple is given for multi-phased clocked charge pumps showing that a relatively small parasitic capacitance mismatch will result in a sufficiently large output error ripple. A simple method for eliminating the ripple caused by a mismatch of parasitic capacitance is presented. The principle of DGB is experimentally verified through the implementation of a low-voltage, programmable gm-C biquad filter.