Patent ID: 7977954

Claim:
A system for measuring a plurality of measurable capacitances, the system comprising: at least one passive network coupled to the plurality of measurable capacitances; at least one charge changing circuit coupled to the at least one passive network; and a controller, the controller including a plurality of digital outputs coupled to the plurality of measurable capacitances, wherein the controller is configured to perform, for each of the plurality of measurable capacitances, a charge transfer measurement process comprising: repeatedly applying an associated voltage to the measurable capacitance using an associated digital output in the plurality of digital outputs, accumulating charge on an associated passive network of the at least one passive network by repeatedly sharing charge between the measurable capacitance and the associated passive network, generating quantized values by repeatedly measuring a voltage on the associated passive network using a quantizer having at least one threshold, repeatedly changing charge on the associated passive network by a quantized amount of charge using an associated charge changing circuit of the at least one charge changing circuit, the quantized amount of charge based on the quantized values, and digitally filtering the quantized values.