Charge domain successive approximation analog to digital converter

Abstract

A charge based analog to digital converter includes a plurality of charge storage elements, each having a charge receive mode and a charge expel mode, and were in each of the charge storage elements is configured for storing a predetermined amount of charge. There is preferably a two to one ratio between the storage capacity of adjacent charge storage elements. A comparator includes a sensing diffusion connected to all of the charge storage elements. The comparator produces a '0' bit if the sensing diffusion is in a first condition, and a '1' bit if the sensing diffusion is in a second condition. Selection electronics connected to the charge storage elements selectively and successively set the individual charge storage elements in the charge expel mode to successively test the charge quantity stored in each charge storage element by the initial analog charge packet.