PIC sinking voltages higher that Vdd???

[skimask]

Hey. Sorry to bother you again.
I have just looked in Electrical Characteristics, but i cant seem to find my answer I think it might be the thing called "clamp current" or sth. but im not sure. I tried looking it up by Google without any luck, too.
Can you please tell me the parameter i should be looking for please???
Thanks in advance!!!!!!!!
Manuel

1st page of that section, on the datasheets I've looked at so far, it's usually the 3rd parameter.

[malc-c]

Typing something like "driving piezo buzzer from pic micro" into Yahoo returned some interesting hits.

http://www.talkingelectronics.com/Pay/PIC/P6extra.html

I wouldn't expect the Piezo to draw much current, so a single transistor as DT suggested would be fine. If you want to drive things like motors then you could used an H-bridge or a Darlington power transistor.



For your Piezo you could omitt the 18R resistor and output transistor, and connect the buffer transistor's emmiter to the 12v (or 9v in your case) supply

More info can be found at http://www.talkingelectronics.com/Pa...PIC-Page3.html which explains the reason for using two or more transistors for high current loads.

Hope this helps