Variable capacitance switched capacitor input system and method

摘要

A variable capacitance switched capacitor input system and method includes a differential integrator circuit having first and second input summing nodes and a variable sensing capacitor; one terminal of the variable sensing capacitor is connected to one of the nodes in the first phase and to the other of the nodes in the second phase; an input terminal connected to a second terminal of the variable sensing capacitor receives a first voltage level in the first phase and a second voltage level in the second phase for delivering the charge on the variable sensing capacitor to the first summing node in the first phase and to the second summing node in the second phase and canceling errors in a differential integrator circuit output caused by leakage current.