Self Calibration Capacitance Meter

This paper describes a self calibration method for capacitance measurement on the base of MCU. The method uses a software calibration technique for first order errors elimination as: offset and gain error, error caused by supply voltage variations, uncertainty error of comparator’s threshold voltage and its temperature drift as well as uncertainty and temperature drift of resistance. The method do not removes absolute measurement error of capacitance of the reference capacitor. Remaining sources of errors can be leakage currents of I/O pins of MCU, nonlinearity of applied passive components and discrete quantization error of ±1 instruction cycle. The measurement resolution is 16 bits.