Patent ID: 7902842

Claim:
A system for measuring each of a plurality of measurable capacitances, the system comprising: a passive network, the passive network comprising at least one integrating capacitance and an isolating impedance statically coupled to the plurality of measurable capacitances, the at least one integrating capacitance configured to accumulate charge received from the plurality of measurable capacitances through the isolating impedance; and a controller, the controller including a plurality of digital outputs, each of the plurality of digital outputs coupled to a measurable capacitance in the plurality of measurable capacitances, the controller configured to measure each of the plurality of measurable capacitances by performing, for each selected measurable capacitance in the plurality of measurable capacitances, a charge transfer process for a number of times equal to at least two and a measuring process for a second number of times equal to at least one, wherein the charge transfer process comprises applying a pre-determined voltage to the selected measurable capacitance in the plurality of measurable capacitance with at least one of the plurality of digital outputs and then allowing the selected measurable capacitance to share charge with the passive network such that charge from multiple charge transfer processes accumulates on the at least one integrating capacitance of the passive network, and wherein the measuring process comprises quantizing a representation of a charge on the passive network to measure the selected measurable capacitance.