LM3478 Design, noice

Arnold Zender

Other Parts Discussed in Thread: LM3478

Hi,

I have a new design for the LM3478. Vin: 11...13V, Vou: 33V, Iout 0...250mA.

I ussed a 390uH coil. Cin = 30uF, Cout = 33uF. Rloopcomp: 100R, Cloopcomp: 10nF.

RFA: 100K, Comp: 27K + 2n2

Running so fahr well.

Problem: noise in in different areas of the Current from 0 ... 250 mA.

I changed Rloopcomp from 100 to 4K

I changed Comp with different values.

What can I do ?

Thanks a lot.

Best regards

arnold zender

0 Murray Roose over 9 years ago

Hi Arnold,

Can you please send me a copy of your schematic? Would it also be possible to send me plots of the Inductor Current and the Fsw when you have noise?

Is there any reason why you chose such a large Inductor as well?

Thanks,

Murray.

0 Arnold Zender over 9 years ago in reply to Murray Roose

Hi, Murray,
how do I send drawings ?
I had 150 uH before with the same problem. The working current is mostly less than 250 mA.
regards
arnold

0 Murray Roose over 9 years ago in reply to Arnold Zender

Hi Arnold,

Please send me an email directly to murray.roose?ti.com => replace the ? with @.

Thanks,
Murray.

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