Fellows,
We have just assembled a batch of boards which have three LMR16006Y based power supplies each. They are designed to output 3V3, 5V4 and 10V8.
So far we tested 3 different boards, and all of those circuits are generating fixed 3.3V output.
The parts were ordered as ADJ, and the IC marking shows D02Y (first concern here, for the datasheet says it would be Q02Y).
Image below shows the 10V8 assembly. The layout has not only been approved by colleagues on this forum, but also working well in many other projects we have.
The feedback resistors have been suggested by Webench, confirmed by calculations, and the measured feedback voltage is as expected, at 0.775V. The scope signal on the inductor shows a square wave just as expected, at 1.95MHz - however, the duty (~27.9%) is not able to generate the calculated output voltage - instead producing this fixed 3V3.
(SPOILER ALERT: problem is solved)
The feedback resistors shown in the picture do not have the required values to produce 10V8. They should be 143K / 10.9K instead. While checking the SMD marking values for those parts, we figured out the problem - but since this post was 85% ready, I decided to leave it here as a lesson to be shared.
Regards
Bruno
