Computationally Efficient Determination of D/A and A/D Noise in Digital Transmultiplexers

Component inaccuracies in the D/A and A/D converters found in digital transmultiplexers introduce noise to the signals being converted. When the imperfections considered include finite impedances of current sources in switched current source R/2R ladders (equivalent to nonzero impedances in switched voltage source converters), the number of computations needed to find the error at every level increases greatly. This paper presents a method to calculate error at every level with a reasonable amount of computer time by use of multidimensional Taylor series. In addition, an example of computing noise in 13 bit offset binary converter using statistics of group signals is given.