Hi,
There's one parameter Tcomp on the datasheet as below. I'm confused for it's meaning. Does it mean the active time for the input signal (the input should keep stable for this time as a valid signal)? Like a de-glitch function?
Or it means a delay time for the compactor to output(from input to output)? Or just a delay time from the first wetting current to the second wetting current?
Many thanks.
Brian Zhao
Hi Brian,
At the end of the wetting current application for each of the enabled channel, the input voltage is sampled by the comparator.
The tcomp time is the time needed for the comparator to sample and compare the input, then output the result and store the result into the registers.
What is your application scenario?
Thank you,
Helen
Hi Brian,
If customer is seeing a glitching issue, you should consider using the detection filter function. You can set the CONFIG register so that switch status change interrupt happens only if the same status was read 1~4 times( you can set how many times the same status need to be read). Please see below snippet from datasheet explaining the function:
Below are to address your questions:
1. So the input signal should keep stable during this tcomp time, correct? What if any change during this time?
- Correct if you are not using detection filter. If you have a change glitch in status I suggest using the detection filter function.
2. Also the picture you showed there's another tcomp, is it the same with the one you marked in red?
-Yes. Red arrow is indicating where should the tcomp time be considered( sample at near end of wetting current application), the black tcomp is to indicate how long is the timing comparing to the wetting current applied time.
3. In continuous mode, when was the input voltage sampled?
- Near the end of the wetting current application. The wetting current active timing would leave sufficient time for tcomp to do the sample and compare action.
Please let me know if this helps.
Thank you,
Helen
