On Mon, 2 Feb 2009 09:34:01 -0800, "Joel Koltner"
wrote:

"John Larkin" wrote in message
.. .
Here's The Brat's first PCB layout. U1 is an LT3580 in the leadless
DFN package. It's working as a Cuk inverter, making -2.5 from +12.

Nice. Did you guys hand solder that board or use paste and an oven? I've
done leadless DFNs by hand, but I choose the QSOP package for mine since it's
easier to hand solder.

That was stencil pasted and reflowed. My production people found an
outfit that makes cheap laser-cut stencils out of mylar. They don't
last as long as stainless, but are as lot faster and cheaper. And they
know we're probably going to change something on the board sooner or
later.

I'm not a great fan of DFNs, but somebody picked this one for some
reason.


This is a very cool part.

Agree -- "it just works," which is more than I can say for some switcher IC
I've used.

That's your ~DC to 1GHz amplifier board, isn't it, John?

Yup. Really DC, not ~DC!

What uses the -2.5V?

The opamps. It's a gross overkill, as we need maybe 50 mA.

John