Pinout
Piezo buzzer (2-pin) pinout
Pins
- − (negative/ground lead — the shorter leg)
- + (positive lead — the longer leg, under the "+" moulded on the top)
Specifications
| Type | Active (built-in oscillator, DC) or passive (needs square wave) |
|---|---|
| Rated voltage | 5 V typical; 3.3 V and 12 V versions exist |
| Current | ≤ 30 mA (5 V active type) |
| Resonant frequency | ≈2.3 kHz (common 12 mm active type) |
| Sound level | ≈85 dB at 10 cm (12 mm active type) |
| Size | 12 mm Ø × 9.5 mm (common 12 mm type) |
| Polarity | Longer leg = + |
Notes
- Active buzzers just need DC applied and buzz on their own; passive buzzers need a driven square wave (PWM) at the desired frequency. Same canister, so test: a passive one only clicks on DC.
- An active buzzer draws ~30mA — fine straight from a GPIO on most boards, but add a transistor for the louder 12V types.
