Segmented Digital Step Attenuator for Glitch Reduction

The patent divides the binary-weighted attenuator stages into multiple sub-stages, where each binary stage is further segmented into parallel paths. This segmentation allows the switching transitions to be distributed across multiple smaller steps rather than occurring simultaneously in a single binary stage, thereby reducing the amplitude of switching transients while maintaining the compact binary-weighted structure.

The patent merges the advantages of both binary-weighted and thermometer-coded approaches by combining segmented binary stages with selective thermometer-like switching within each segment. This hybrid approach achieves transient reduction similar to full thermometer coding but with fewer total stages by leveraging the logarithmic compression of binary weighting, thus merging the compactness of binary with the glitch-reduction of thermometer coding.

The patent applies preliminary action by pre-charging or pre-discharging certain capacitor elements before the actual switching event. This preparatory action ensures that when the switching element transitions, both turn-on and turn-off occur more symmetrically and rapidly, as the energy storage elements are already in optimal states, eliminating the need for one-sided optimization of turn-on speed at the expense of turn-off time.