What's the -5V output on a computer power supply for?

Question

This -5volts is usually very low amperage (0.3 to 0.5 amps.)

This negative 5 voltage was used in most HP and Compaq computers a few years ago....2000, 2001, etc.

But now, I noticed the -5 volt output does not exist in the new PSU's. But they still have the -12volt output.

Anyone know what the -5V output is used for in older PC's?

My 2000 HP Pavilion XL866 AMD Athlon needs a replacement PSU and the old one has the -5V @ 0.3 Amps. So, I guess I'd better find a replacement PSU that has the
-5v.

Answer 1

The -5V supply was from the days when single supply op-amps weren't as stable as dual supply op-amps. You used to have to have a -5V supply as well as the +5V for a dual supply op-amp. Single supply op-amps only need +5V and 0V, so the -5V isn't as needed, although you will still find some devices using dual supply op-amps for more resolution at their output.

Answer 2

nice question..........