Hi Folks,
it's kind of a follow-up thread of this thread:
The circuit has worked beautifully for the last 5 years in hundreds of our products. But right now we have trouble with defective REF3133. Some of the outputs seem to be destroyed and emit permanently 0V, even when the regular load (<6.2mA) is desoldered. We wonder whether there have been made changes in the REF3133 in the last months?
The top marking code of the defective REF3133 is "R31F" with a horizontal line above the "R" and a horizontal line below the "3" and the "F". On the bottom of the packages of the defective REF3133 we found "61P5", "65P1" and "68P2".
Are there any known problems with these REF3133?
The present circuit looks like this:
The caps are X7R. The FB is a small ferrite bead.
Kai