On Sun, 08 Jul 2007 19:26:32 GMT, "colin"
wrote:


"John Larkin" wrote in message
.. .
I need to make -12 from +12, at maybe 500 mA, and all the obvious
inverting switching regulators suck for one reason or another.

The LM5112 is a 50-cent fet gate driver.

John

have you considered a MC34063A ?

might just do it wothout an external switch.
input range 40v, for voltage inverter just connect ic ground to neg op.

Colin =^.^=


Yeah, I looked at that. It would probably work, but it's an old, slow
bipolar part with a darlington switch, so it would be pretty
inefficient and would run at maybe 100 khz, so it would need a big
inductor. But it is cheap, 35 cents or something.

Thanks.

John