Abstract: A signal conditioning unit receives index and data signals from a rotary incremental encoder, and attenuates the pulse-to-pulse jitter of the data signal by passing the data signal through an AND gate having at least two of its inputs tied to the data signal to provide a jitter attenuated data signal. Zero-delay jitter riding on the index signal is attenuated by ANDing together the index signal and the jitter attenuated data signal to provide a jitter attenuated index signal. The jitter attenuated index signal is then processed to extend the active state of the signal to match the duration of the active state of the index signal, and thus provide a synthesized jitter attenuated index signal. To account for the propagation/processing delay associated with extending the active duration of the jitter attenuated index signal, the jitter attenuated data signal is delayed to provide the proper timing relationship between the processed jitter and index signals.