The present invention provides a system for adjusting a selectable capacitance of a variable capacitance array to compensate for voltage non-linearity of the variable capacitance array. In general, the system includes the variable capacitance array and a calibration circuit. The calibration circuit operates to determine a voltage across the variable capacitance array and to generate a capacitance selection signal based on the voltage across the variable capacitance array and a known capacitance versus voltage characteristic of the variable capacitance array.