An improved
system and method of performing
capacitance measurements that provides a fast digital response and a reduced output error. The
capacitance measurement
system includes a circuit configuration that has a
variable capacitor and at least one reference
capacitor connected to one another at a common node, which in turn is connected to the input of an analog-to-
digital converter. The circuit configuration further includes an array of switches coupled between the variable and reference capacitors and the supply
voltage, a reference
voltage, and ground, respectively, The switched variable and reference capacitors are employed in conjunction with the A-to-D converter to perform, at the common node, a plurality of
voltage measurements for use in generating an expression defining the
capacitance of the
variable capacitor, The generated expression of variable capacitance is independent of a number of specified output error sources including but not limited to a sample-and-hold capacitance, the
parasitic capacitance at the input of the A-to-D converter, a sample-and-hold offset voltage, and the leakage current at the input of the A-to-D converter.