High resolution, high speed, low power switched capacitor analog to digital converter

摘要

An analog to digital converter includes first and second converter segments having respective first and second arrays of binary weighted capacitors. Each capacitor of the first segment has a first electrode connected to a first common node and a second electrode connected through respective switches to one of a first reference voltage terminal and an input terminal. Each capacitor of the second segment has a first electrode connected to a second common node and a second electrode connected through respective switches to one of the first reference voltage terminal and the input terminal. The converter includes a coupling capacitor connected between the first and second common nodes and capacitance means connected between the first common node and a reference voltage terminal. The coupling capacitor and capacitance means have capacitances, Cs and CATT respectively, that substantially satisfy the relationship: (2<p>-1).Cs-CATT=2<p>.C, where p is the number of bits coded in the first converter segment and C is the unit capacitance.