Our customer will use ADI16209 and he selects ADP1712 as FAQ: ADIS1620x/21x/22x Power Supply Considersations.
Our customer's test result was that ADP1712 with external 2uF outputs rush current of ~2A peak at start-up.
If Wattage ( themal problem ) is little, is not there any problem with rush current ?
Or does the test at https://ez.analog.com/docs/DOC-11900 include external component to protect against rush current ?
Thank you for your asnwer.
Thank you for your post and for your support! If your customers is observing a peak current of 2A, then they must have a very fast ramp time on their supply (3.3V in ~3.3us). Why does this need to be so fast? While we do recommend quick and clean transitions, I would think that this could be in the 50-100us region and still work fine. Of course, we always recommend thorough testing in the final configuration.
On your question (below), I would recommend that any limitations be clearly defined, before we trying to determine what to do about these limitations. If there is a limitation in the "wattage" of the power supply, what is that limitation?
Given the relatively low energy that is put into the 2uF capacitor, I would not anticipate thermal issues, unless the customer has extremely thin wires or traces. I would probably concern myself with the current limit threshold and recovery behaviors of the customer's power supply, in order to make sure that this does not cause instability or other strange response characteristics (which could be damaging, per device absolute maximum ratings in the datasheet).
I hope that this helps!
You are welcome! Glad that this helped.