Fast test method for serial A/D and D/A converters

An efficient test method for so-called serial analog/digital (A/D) and D/A converters which can be executed on digital automated test equipment is described. The method is applicable for stand-alone converters and for mixed-signal devices containing this type of converters. The proposed solution makes use of some special properties of serial converters. The method consists of a measurement of the output quantity at a number of stationary inputs, distributed over a full input range. The static transfer curve is determined by a number of DC measurements. An accurate DC source is required for testing the sigma-delta modulators, and a low-speed digitizer is needed for the serial D/A. In addition, simple computations must be performed on the acquired data (Fourier transforms are not necessary). A reduction of test time and computational effort is claimed, still giving sufficient information on gain, offset, noise and distortion