Control voltage standards?

[solderfumes]

I'm thinking about building a dedicated LFO for use with control voltage inputs on pedals.  In particular, I have a TAPLFO chip that I'd like to box up into a module that I could use with other pedals like flangers, tremolos, phasers, etc.  I'm just wondering what is the "standard", if there is one, for control voltages in synths/etc.  A friend of mine says that it's 0-5V on his Korg synth; the TAPLFO datasheet gives a circuit for a -5V to 5V output.  Anyone else have suggestions?