Techniques for residue-to-analog conversion for residue-encoded digital filters

The paper describes two techniques for converting samples from a residue number code to an analog output signal. The first technique employs the mixed radix representation as an intermediate step, and then forms an analog output sample using several short word length A/D converters and an analog summing circuit. The approach is attractive for residue systems with a large number of small moduli where it is desired to translate to analog form as directly as possible. The second approach uses the Chinese remainder theorem to convert from residue to a weighted binary code for the case where the binary is needed, or when a standard A/D converter is to be used. Several particularly simple forms of this technique are available for two and three moduli systems where the values of the moduli are chosen carefully to simplify the hardware. Finally, a hardware feasibility model of an R/B converter is described and the principles of operation are verified.