SparkFun Forums

[kajsng]

Hey. I need to convert a signal that's either 0 or 5 to -5 or 5. Is there some type of inverter chip that I could buy that would do that? (input of 0v should produce an output of -5v, input of +5 should produce output of +5v)
Thanks.

[jasonharper]

Any chance you could reverse your two input states (so you'd have 0=>5, 5=>-5)? That's easily achievable with a PNP transistor and two resistors.

You really need to specify how much current you need from the output, and the maximum frequency at which it needs to change state. The simplest solutions will tend to be limited in these respects.

[leon_heller]

You should be able to do it with a comparator, or an op-amp wired as a comparator.

Leon

[kajsng]

Any chance you could reverse your two input states (so you'd have 0=>5, 5=>-5)? That's easily achievable with a PNP transistor and two resistors.

You really need to specify how much current you need from the output, and the maximum frequency at which it needs to change state. The simplest solutions will tend to be limited in these respects.

Yup, the states could be reversed as you specified.

I'll need ~0.5A output, and the frequency shouldn't be more than 5000 Hz.

[jasonharper]

You need the half amp in both output states, I suppose? No one-transistor solution is going to work, then - one of the states is produced by a pull-up/down resistor, which isn't practical at that current level.

My thought would be a half-bridge IC of some sort, but couldn't find a suitable one in a brief search.

If you could find an op-amp with rail-to-rail 0.5A output capacity, it could be used as a comparator (connect the other input to approximately 2.5V).

A SPDT analog switch with well under 10 ohms on-state resistance could do the job - they can generally be wired to switch voltages that go both positive and negative from ground. Maxim probably has something suitable.