I'm loking for an rail-to-rail OPAMP to my project. I need a OPAMP that fed by a 12V and a -5V power supplies can generate an output voltage near these values, at least, near the positive 12V, the value of the negative source is not needed to be reached at the output.
On the digikey's web site, to filter my search , I came across with the following filter:
- differential, rail-to-rail
- push-pull, rail-to-rail
- rail-to-rail
What is the difference between them ?
Best Answer
A differential op-amp has two outputs, one that works the usual way, and another whose voltage goes up when the main output goes down and vice versa. They are useful for driving differential ADC inputs, driving differential transmission lines, etc.
A push-pull output op-amp is the usual kind, whose output is capable of both sourcing and sinking current. Probably many of the ICs that aren't labeled with this feature have it anyway. For the devices where it's mentioned, somebody probably thought these op-amps might be listed in the same selection table with comparators, since many comparators have open-drain outputs and aren't able to source output current.