A Calibration-Free Mismatch-Immune Quadrature-Clocked Voltage-Dependent Capacitance Measurement Method

In this paper, we propose a calibration-free mismatch-immune quadrature-clocked voltage-dependent capacitance measurement (CFMI-QVCM) method. It is specially applied to extract and separate MOSFET gate capacitance with high accuracy. Through introduction of a simple input signal converter circuit and a special way to achieve capacitance extraction, we can avoid extra calibration steps which mean additional measurements, and meanwhile the mismatch errors from both inner devices and outer measurement equipment can be eliminated. A simple dual-channel selection module is designed to complete capacitance separation. To improve area utilization, an addressable array is introduced. Furthermore, our design is compatible for on-chip high-frequency measurement signals which is necessary for further smaller capacitance. Measurement results show that our method increases the accuracy by tens of times.