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LNK304 output dips

Posted by: paul.catijn on

Yesterday I issued an topic about powerdips due to switching a load on a LNK304

A have a few extra questions:
1: I have added an continues load of 20 mA, this makes the dip on the swiching load (100 mA) much smaller. It seems that the dip depends on the time relation between the FET switching and the time of switching the load. I we switch the load just after the FET has been on the dip is very large if we switch just before the FET will go on the dip is very small
By adding a 20 mA continues load the FET switche in a much higher frequency and the DIP are always relative small.

2: We want to have 220 UF on the output, to give some extra buffer, but this is not recommended in the app note (not more than 100) What problems can we have and is their some way to verify if we have this problem on our design?

3:In your answer from yesterday you suggest to use a TL431V (1.25 mV ref) but if see the datasheet it says it 2.5V The V version also seem difficult to buy at least not at Digikey and Farnell

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