LM3478: My LM3478 design doesn't work very well.

Jerry Cao

Part Number: LM3478

This is my circuit diagram,

and this is my pcb lay out.

I encountered some problems，sometimes I can get HV about 150V.but if I touch some part of this PCB .it doesn't work at all .I can only get the power voltage. I remove all the electronic component,and then weld them on the PCB without change anythings.It works again. I feel so strange.

And then I make another PCB. it doesnt work at all.

It is a part of one PCB. It uses the same schematic of the first one.

THX for TI'ers help.

over 6 years ago

0 Youhao Xi over 6 years ago

TI__Guru 73830 points

From your description it sounds like a soldering problem: some part may not get soldered well, because after removal and re-soldering (weld) on PCB, it worked. The blue layout figure does not match your schematic. The red colored layout is not complete and ground connections are not shown, making harder for review.

0 Jerry Cao over 6 years ago in reply to Youhao Xi

Prodigy 50 points

It's kind of u for your help.I have solved my problem. thx again.

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LM3478: My LM3478 design doesn't work very well.