May I use microprocessor GPIO to drive a buzzer?

[wwwrabbit]

I saw some example of buzzer applications. they are not directly connected to microProcessor's IO pin, but through a transistor, and higher voltage on transistoe's collection pole, the buzzer is parallel connected with collection's resistor.

May I just simplify by connect microProcessor's IO pin directly to buzzer? that will make my circuit simple.

Thank you in advance.

 

[IanP]

That depends on the type of a buzzer ..
Buzzers with internal driver can be driven directly from certain microcontroller pins (open drain) with a protective zener diode between pin and GND ..
Buzzers that require external driver should be driven rather by a transistor than directly by a microcontroller pin, and the reason behind it is, that basically they are "capacitors" and microcontroller pin may not have enough sinking current capacity to drive them ..
For some other hints check out this application manual on "PIEZOELECTRIC SOUND COMPONENTS": **broken link removed**

Regards,
IanP