1. A system for determining a capacitance value, the system comprising: a first switch coupled to a first capacitance; a passive network coupled to the first capacitance, wherein the passive network includes an integrating capacitance configured to store charge received from the first capacitance; a charge changing circuit coupled to the passive network; and a controller configured to determine the capacitance value by repeatedly applying a predetermined voltage to the first capacitance using the first switch, repeatedly sharing charge between the first capacitance and the passive network to accumulate charge on the integrating capacitance, repeatedly measuring a voltage on the passive network using a quantizer having at least one threshold and generating quantized values responsive to the repeated measurings, repeatedly changing the charge on the integrating capacitance by a quantized amount of charge based on the quantized values using the charge changing circuit, and determining the capacitance value by digitally filtering the quantized values.