At 04:09 PM 2/6/02 +0000, you wrote:
>Hi guys'n'gals,
>     Has anyone got any neat ideas on how to a +5v to -5V converter for a
>power supply. Only a few milliamps required on each rail. It's a once off
>for something I'm trying at home. I did try just splitting the supply but
>for some reason the positive circuit didn't like it (it wouldn't work!).
>I must invest in a dual rail PSU sometime!
>Any thoughts appreciated,
>John


Easiest thing is to slap an ICL7660 and a couple of caps in there.
http://pdfserv.maxim-ic.com/arpdf/ICL7660-MAX1044.pdf

If -3V is ok you can use a hex inverter as an oscillator and a charge pump
using a dual diode, and save a few pennies. Or feed it a reasonable clock
signal that you may have on the board elsewhere.

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
9/11 United we Stand

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