This part has a page of its own, with a note on using it and a circuit to try: the part page.
Buzzer (active)
A 5 V active piezo buzzer: apply DC the right way around and it makes its one note.
An active buzzer has the oscillator built in, so electrically it is not a speaker at all. It is a polarized resistive load that conducts, and sounds, only while its positive leg sits above its negative leg. That is exactly how it is modeled: a resistor that conducts one way, goes high impedance the other way, and reports sounding or silent with nothing in between.
Pins
| Pin | What it does |
|---|---|
1 |
The longer leg, positive. |
2 |
The shorter leg, negative. |
Properties
None.
What the model gets right
The buzzer really loads the net it is on, the same way the LED does, and that matters for a common mistake: driven straight off a 5 V rail it takes about 31 mA and sounds, but with the usual "LED resistor" of 220 ohms in series, the divider it forms leaves only around 2 V across it (below the threshold it needs), so it goes silent rather than merely fainter.
What it does not model
No audio waveform and no volume. The probe reports sounding or not sounding, nothing in between, and no reverse current or capacitance either.
The two numbers behind that are both round rather than measured from one part. The element is a plain 160 ohm resistor while it conducts, which is the round number next to the 167 ohms a 12 mm 5 V buzzer's rated 30 mA at 5 V works out at, so it draws 31 mA on a stiff rail. It is called sounding at 2.5 V across it and silent below, which is half the rated supply and stands in for the 3 V to 8 V operating range those datasheets quote. A real buzzer fades out over a volt or so rather than stopping at a line. There is no frequency at all: a real active buzzer's note is somewhere near 2.3 kHz and this part has none.
Common mistakes
Putting a series resistor in front of it, the way you would for an LED. A buzzer needs the full rail across it to sound at all; a resistor sized for an LED usually just silences it, which is the exact mix-up that makes people think the buzzer is dead. For a piezo element that actually needs a driven tone, see the passive piezo.
See it in action
Doorbell and Parking sensor both drive an active buzzer straight from a GPIO pin with no series resistor. See them at /templates.