Criticize SMPS PCB Design

Yes, it is me again with a PCB Design. I am learning a lot thanks to you. This time, the specs are;

• 10-32 V input
• 35V 4A output
• Boost converter
• The controller IC is LM3478.

Schematic & PCB:

Q1 has a breakout board footprint. R1 and L1 are on the solder side. The ground line of 100 th under Q1's footprint is going to be covered with a lot of solder. Q1 and D1 are connected to a heat-sink. This is going to be a home-made single sided PCB.

LM3478 Datasheet

IXTH24N50 Datasheet

CTB-34 Datasheet

• Are the JIN/JOUT connectors smaller than the silkscreen mask? If not, it looks like both C5 and C7 aren't going to fit on the board... ? – darron Sep 6 '11 at 17:51
• Why the close vote? It seems a reasonable question and on topic to me. I'd answer, but this question looks like you have to spend some time to give a good answer and I've got three customers breathing down my neck today. – Olin Lathrop Sep 6 '11 at 18:27
• I see closing since 1) the layout is his; there isn't a specific question which is likely to be helpful to others in the future 2) there isn't a specific question, just a "check my work" statement. – Brian Carlton Sep 6 '11 at 20:02
• @Brian Carlton Since the design is already on the site, the question would be helpful to other people who believe that a good way to learn is to see already existing designs and avoid problems appearing in them. – AndrejaKo Sep 7 '11 at 8:57
• @abdullah kahraman Well, this question was well accepted, so I don't think that there's anything wrong with your question. You just had the misfortune to ask it when hostile users were online. – AndrejaKo Sep 7 '11 at 9:32

1. The MOSFET you've chosen is overkill. A 35V output application will not need a 500V MOSFET. Try something in the 100-150V range, which will have lower gate charge and $R_{DS(on)}$.