Ac to DC without transformer

Hi, I was wondering if there were any single chip solutions to convert from 120V AC to DC We are currently using a transformer but its a bit bulky to put on a printed circuit board. The chip will have to provide 5V DC for a couple of IC's.

0.1A is maximum current required.

Thanks in advance.

Reply to
Foaad
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Do a web search on off line power, or off line switcher. Lots of info.

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Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
Reply to
Tim Wescott

At these power levels (1/2 Watt), switchers aren't much smaller than linear transformers. If ALL of your circuitry is isolated properly, you can consider using series capacitance instead of a transformer, but you'll need about 3uF, and properly rated capacitor(s) could also be about as large as a 1VA transformer. You might want to put your energies into looking for the smallest possible linear transformer, especially if your product has any exposed metal. Paul Mathews

Reply to
Paul Mathews

No single chips that I know of, but check out Power Integrations and their LNK304 series of chips

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This takes at least 10 other components to make it work, but it works well and they are cheap solution.

At .1A you need too big a series cap to do a simple ac coupled bridge converter for it to be cheap, however, if you can lower current to about 20ma it is a good way to go.

Of course I'm thinking you don't need isolation?

Rocky

Reply to
Rock

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