One last thing to this topic: If you need a level convertor fast and now, like you did, you can also use interesting two-transistor levelshifter circuit, instead of that problematic "OC gate" circuit.
Look at the schematic: There are two transistors. The lower one also needs a base resistor, when drivin from CMOS logic (like a microcontroller).
You can use also smallsignal MOS transistor, like 2N7000 or BS170, then you will not need any resistor. Only the upper pullup, which might by a few kiloohms.
The diode might be a 1n4148 or so, better a smallsignal schottky (bat42 etc), to get lower saturation voltage, VOL(max).
And how does that work? Simple. The lower transistor (NPN or N-MOS) work just as the inverting OC logic gate we've seen before. But the output voltage is then fed to an emitter folower (yes, there MUST be an bipolar junction transistor, NPN). The Em. follower will give you very low impedance high voltage.
The only issue is that it gives you output voltage of Vsupply minus BE junction drop (0.6V) minus base current times the resistor voltage drop (which is mostly negligible).
When you switch on the lower transistor, the load capacitance (connected to the output) is then discharged rapidly through the lower transistor and the diode. (the upper T. Em. follower is therefore disabled, he has almost zero volt on his base).
So this circuit is inverting (easily overcome be simple software mod in the microcontroller) and has a powerfull low impedance output capable of FAST driving high capacitive load, such as power mosfets! Yes, this can be used as simple gatedriver for a power mosfet like IRF3205, or so. Just put appropriate supply voltage, for power mosfets use 12 to 15 volts. Don't forget to add appropriate gate series resistance. This driver is simple, but can drive power mosfets at tens of kilohertz, unlike all the simple "OC like" circuits, which people usually use without knowing any of the issues with that.
I hope, this circuit might help someone, not many people have this circuit ready for use in their mind, when designing projects.
Note: I wouldn't bother to use this circuit for level converting for logic circuits. Just too many components involved for one signal line. But very handy for mosfet driving or other similar stuff. The output is very powerfull, can deliver a hundreds of miliamps in a pulse. Really sharp edges, but be careful not to overrun maximum peak currents for the transistors!