FEDEVEL
Platform forum

juanjo , 10-14-2015, 08:08 AM

Hello all.

Sometimes I see on some demo board schematics some components marked as "DNF" or "DNP". In the Switching Power Supply Design Course there are also some of these type of components.

I am struggling to understand this concept.

What is the purpose of this? When a designer might mark a component as "DNF"?

Thank in advance.
Juanjo.

robertferanec , 10-14-2015, 08:18 AM

Hello @juanjo, DNF = Do Not Fit / DNP = Do Not Place.

The idea is, that you have one schematic, one PCB, but you can build more variants of your board (depends which components are fitted and which are not fitted). For example, in the case of Switching Power Supply Demo board, you can build a board variant with wide input voltage (6-24V) or a board variant for a single 5V input.

Maybe have a look at this video, it will help you: Altium Tutorial – Variants & Printing PDF Schematic

juanjo , 10-14-2015, 08:44 AM

Thank you very much for your answer @robertferanec.

So in effect, these components are placed if that variant is used, isn't it?

robertferanec , 10-14-2015, 08:48 AM

Yes, you are correct. These components may be placed in a different variant, but are not fitted in the current one.