When the current through an inductor is interrupted in theory an infinite voltage is produced for zero seconds, in pactice a resonant circuit it formed with the parasitic capacitance in the inductor, the maximum voltage is simply the Q multiplied by the applied voltage.

There are many other manufacturers around but MAXIM make step-up regulators with input voltages as low as 0.7V
http://para.maxim-ic.com/cache/en/results/4631.html

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Yes, maxim has many dc to dc step up converter, but many of them are QSOP package.
Does anyone have idea how to solder a QFN ic? That's too small, I have not idea..

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bananasiong

 

I think you can use an oven maybe? Hot air? Either way it seems you require solder paste which is a pain in the ass.

I think I also heard somwhere to run the traces so that they extend beyond the edges of the chip, then you can just use a soldering iron.

 

But QFN seems to be 'Flat No Lead' type, need very strong soldering skill. If I use UV type PCB, do I need to remove the green film before soldering? Usually I don't remove it, but sometimes it cause the soldering iron to be dirty if u give too much heat.

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bananasiong

 

They do ready-made evaluation boards for some of the more popular ICs but they're expensive but worth it if you want to save the effort.

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I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

Before the Holidays I looked thru the MAX collection and came to the same conclusion that there are very few with DIP packaging. But there are a few: I did get 3 to play with, the MAX633, MAX643 and MAX743.

Haven't done anything with them yet, got a few other projects to complete first.

-- Dan

 

Here are two piccies attached with a joule thief i built a while ago and still has a blue LED going reasonably bright at 0.377 Volts.
A half full AA battery lasts for about 2 days.

http://i123.photobucket.com/albums/o...O/DSC02024.jpg

http://i123.photobucket.com/albums/o...O/DSC02023.jpg

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There are more ways to get to Rome.

Electricity, Electric clocks, Meters and Trains are great.

Please don't sent me private messages, I will not answer them.
The questions asked can be discussed in the open forums.
http://www.youtube.com/user/RODALCO2007 some interesting electrical stuff to watch.

 

Wow I bet that ferrite core inductor radiated a lot of RF energy.

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I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

Wow, is that super bright?

Hero999, do you mean this coil can interfere with other RF devices?

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bananasiong

 

Yes........

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I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.