Separate access feedthrough from conversion glitch
Digital activity can disturb an analog output without a new DAC value becoming effective. ADI describes digital feedthrough as coupling associated with activity at the digital interface. The relevant question is whether access occurs, rather than only whether the DAC core has received a new output code. A loading operation and a quiet analog output are consequently different statements.
Conversion glitch has another origin. During a change of code, the internal switches involved in the conversion do not all propagate their control changes identically. Their temporary intermediate relationship produces a disturbance at the output. This mechanism belongs to the transition inside the conversion path. It should remain distinguishable from digital-interface coupling even when both disturbances appear around an access in a particular application.
That separation makes a disturbance requirement more precise. An application can care about activity during unchanged-code access, activity when a new code is applied, or both. Asking only about output update timing leaves the feedthrough question incomplete; asking only about serial-interface activity leaves the internal switching question incomplete. Name the mechanism being assessed before comparing a quoted glitch descriptor or treating a synchronized update as a description of analog quietness.
Describe glitch area without substituting a peak
A glitch can be described by its net area rather than only by its largest excursion. ADI's discussion uses this area-based description to characterize the disturbance over time. The descriptor therefore retains information about the time course, including the relationship between contributions of different polarity. It is not simply another name for the maximum instantaneous voltage reached during the event.
Two descriptions can accordingly emphasize different attributes. A peak-oriented requirement concerns the excursion, while an area-oriented requirement concerns the disturbance across the stated event. Collapsing both into a generic glitch size would hide that difference. The terminology in the source must also be read carefully: its use of glitch energy does not justify relabelling the net voltage-time area as physical energy dissipated in joules.
Settling is a further question. It concerns the analog output reaching its required final condition after a change, rather than just the area assigned to a transient. A small net area cannot establish a settled-output result by itself. Retain the actual descriptor and its measurement context when comparing DAC descriptions, so an area requirement, peak requirement and final-output requirement remain separate technical objectives.
Keep the code transition attached
The code transition determines which internal switching paths participate. ADI explains that different changes can produce different glitch behaviour because the switch-control paths and their propagation relationships differ. A descriptor attached to one transition should therefore retain that transition as part of its context. The DAC family name alone does not identify the event used for the description.
A major-code transition is a useful reference in the discussion because it involves a significant change in the internal switching relationship. It should not become an unconditional claim that the same transition always produces the largest disturbance. The source's treatment of transition dependence is more specific than a general worst-case label, and it does not establish a common ranking for every DAC architecture or operating condition.
This distinction matters when a comparison reduces several specifications to one glitch headline. Identify whether they describe the same kind of code change and whether the quoted quantity has the same meaning. The objective is to compare defined events rather than to reconstruct internal switch timing from a code word. No bit-pattern example is needed to recognize that different transition coverage can leave two apparently similar descriptions technically unlike.
Relate repeated access to persistent output disturbance
Repeated access introduces a time-history question beyond the isolated disturbance. ADI explains that a disturbance may not have dissipated before further operation occurs. In the stated application context, repeated activity can then produce an additional output offset. The useful mechanism is the relationship between recurring disturbance and its dissipation, rather than a claim that every individual access permanently changes the desired code.
The access pattern consequently belongs with the analog question. An isolated-event description does not automatically cover ongoing activity, while an observed average shift would not identify whether its origin was interface feedthrough or conversion switching. Keep the mechanism and the repetition context associated. This allows a requirement to distinguish a single transient from the output consequence of repeatedly exciting the same coupling path.
The outcome remains dependent on the device and surrounding application. The source does not make one access rate or one passive network a universal solution. Frame the requirement around the disturbance being repeated and the output attribute that matters, then seek evidence covering that operation. This is separate from choosing which channels respond to a common update: coordinated digital application of values does not remove the physical disturbance or its time-history dependence.
Sources and further reading
ADI AN-1444 saved HTML prose on feedthrough, glitch description, code transitions and repeated operation. Numerical AD5686R case-study results, equations, plots, PCB prescriptions and RC or update-rate recommendations are outside this guide.