-5 and +5V, needed from a single 5V power supply

[toalan]

hi guys I need to get a -5V power rail from a +5V rail, any ideas as to which IC can do the job cheaply?

Regards,

Alan To

[mister_e]

why you need it? for an op-amp or else. Some dc to dc converter will do the job but they're not cheap. you can build something with one 555 ... that's working.

see those links
http://www.electronics-lab.com/projects/power/023/

OR with a simple circuit modification, if your PIC have a extra PWM output you can use it as pulse generator instead of the 555 ;)

[NavMicroSystems]

toalan

an ICL7660 would do the job @ low cost & minimal part count.

see: Datasheet (http://www.intersil.com/data/fn/fn3072.pdf)

If you have a MAX232 on Board and there is a driver spare (like it would be with the BootLoader)
you could even use this spare driver to generate +/- 12V

[toalan]

Sweet that is exactly the IC I am looking for, cheap and minimal parts. yes it is for OPAMPs, I was using an external battery to provide the negative voltage, this make my circuit much less ugly.
You guys rock. Thanks a bundle.

[NavMicroSystems]

Yet another problem solved ;-)

[toalan]

I also used the Max232 to generate the -ve voltage I need. Thanks again Nav for pointing me to 2 possible solutions.