Inverse voltage generator

[RobA]

I got an email from Digi-Key that has what seems to be a new part that could be useful for generating -9V from an input 9V DC. I was wondering if anyone has tried them. Key points are that they are basically an LM78xx voltage regulator (3 pin) but more efficient and if you wire the common and output connections in reverse, it generates a negative voltage! One big feature for us would be that the switching frequency is at ~300kHz. The only place I can find them in the US is Digi-Key and Future Electronics at about $5.

Here's a link,
http://www.cui.com/product/resource/p7805-s.pdf

[jkokura]

Putting them in figure four, using two of them... rad. Clean power, with +/-9V...

That's cool. I'm putting that on my next order from Mouser I think.

Jacob

[stecykmi]

very interesting possibilities with this component. not so cheap per unit ($5.48 each) but you make up the cost with fewer components and smaller footprint compared to 1044-based solutions.

[RobA]

They are about $1US cheaper at Future Electronics too, but I think that's part of the problem, they just aren't widely available from what I can find. Maybe it's just because they are new. Still, you are right that you make up some cost on fewer parts and the reduced footprint is a really good point. I do think I'll order a couple in my next order to try out.