AVR atmega32 help for OC2 pin

Hello…. i’m doing a project,in which i shall be operating the atmega-32 uc such that the OC2/D7 pin is the output. The OC2 o/p will be used to drive an ultrasonic transmitter,and my tests reveal that the ultrasonic transmitter needs atleast 3V for sufficient range.
Can you tell me what the output voltage of the OC2 pin is ? also,if it is less than 2 V,can u suggest some way of pulling it up ? Can i use a opamp? If yes,which one...bcoz i guess the slew rate will have to be considered,since OC2 frequency will be 40 Khz.

Same as Vcc, what are you running it at?

running it at 5V Vcc...so will it be 5V pk-pk ??

Yes, 5v pk-pk. You don't really need it, but you can also put a capacitor in series with it so there's no offset voltage on the piezo element (a .22uF should do fine) and you may get a better signal.

You can also use 2 port pins, drive one high while the other is low and vice-versa, put the emitter across the pins. This will give you twice the amplitude, 10V pk-pk.