Monolithic A/D and D/A converters suffer from the limited accuracy of the available circuit components. A new self-calibration method allows the correction of the linearity errors of binary weighted current source arrays commonly employed in high speed converters. In order to achieve high calibration accurancy a modified dual-slope method is used. This makes it possible to implement A/D and D/A converters with a resolution of 14 bits or more at a conversion time of less than 14 nannoseconds