28v boost converter

AtomSoft

Well-Known Member

• Jun 25, 2010

• #1

I know i probably asked this but it got lost and searching doesnt help...

I need to make a BOOST STEP UP converter.

Requirements:

INPUT: 3.3v(MIN) to 5v(MAX)
OUTPUT: 27v-29v @ 20mA

Im not asking for anyone to do it for me i need some help in choosing how to accomplish this? Where do i start? What should i be looking for in a IC?

Any tips would be great full, THANKS!!!

 

W

Wade Hassler

Member

• Jun 25, 2010

• #2

Here's one way: **broken link removed**

34063's of all kinds(DIP, SOIC, with/without enable) are under a buck

 

Torben

Well-Known Member

• Jun 25, 2010

• #3

Hi Jason,

Seems like the kind of thing you would be able to modify a Black converter to do: 2-transistor Black Regulator

There's a list of hints on the page geared toward making it work at higher voltages than the main one on the page.


Good luck!

Torben

 

M

mneary

New Member

• Jun 25, 2010

• #4

Wade Hassler said:

Here's one way: **broken link removed**

Click to expand...

I would double check your results from that tool against the data sheet just to be safe. It's a clever contribution but not a substitute for the data sheet and app notes. The tool has error checking for peak current, but not for duty cycle, voltage, or frequency.

Your goal of 3.3V to 29V is pushing the limits. You might find that a transformer (autotransformer) works better than a simple boost converter.

 

AtomSoft

Well-Known Member

• Jun 26, 2010

• #5

the PSP has a LCD which is 28v @ 20mA which is what im using and it runs off 3.7v so im sure its doable...

That Black stuff is BUCK not BOOST and im not smart enough to convert it lol

Wade ... im taking a look now. I had that link before too!

 

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M

mneary

New Member

• Jun 26, 2010

• #6

You need to put in a target ripple value to clear up the NaN (Not a Number, i.e. infinite) output capacitor. The input capacitor should 100 microfarads, not 100 microhenries.

 

AtomSoft

Well-Known Member

• Jun 26, 2010

• #7

Oops lol knew i didnt see something....

"The input capacitor should 100 microfarads, not 100 microhenries. "

Yeah i assumed a nice typo

 

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Last edited: Jun 26, 2010

AtomSoft

Well-Known Member

• Jun 26, 2010

• #8

well im going to order some of these chips to give it a try. Going to have to make some test calculations so i can order some Inductors also... unless i can make custom inductors... any links on thaT?

 

U

Ubergeek63

Well-Known Member

• Jun 27, 2010

• #9

AtomSoft said:

well im going to order some of these chips to give it a try. Going to have to make some test calculations so i can order some Inductors also... unless i can make custom inductors... any links on thaT?

Click to expand...

https://www.electro-tech-online.com/custompdfs/2010/06/pm3600_series.pdf

i can check on my chip fave when i get back to work.