Dynamic tuning of the noise transfer function of high order delta-sigma analog to digital converters

This paper presents a dynamically tuned 3/sup rd/ order /spl Delta//spl Sigma/ modulator to ensure stability and enhance input range. Dynamic tuning is achieved by tuning of the noise transfer function (NTF) through the movement of poles via independently varying the feedback DAC voltages. This method is shown to increase the input signal range by up to 28% over conventional design methods.