Piezo Buzzer
Technical Profile: Passive PCB Mounting Piezo Buzzer
(External Drive / Transducer Type)
1. Classification & System Role
- Component Class: Acoustic Transducer.
- Technology: Piezoelectric (utilizes the reverse piezoelectric effect).
- Operational Category: Passive (External Drive) ā Requires an external oscillating signal (AC or PWM square wave) to generate sound. Unlike "Active" buzzers, it has no internal oscillator.
- Functionality: Tone and melody generation. Frequency and volume are determined by the input signal's frequency and duty cycle.
2. Electrical & Performance Parameters
- Input Waveform: Square Wave (recommended) or Sine Wave.
- Operating Voltage: Typically 3V to 25 V p-p (Peak-to-Peak).
- Resonant Frequency (f Hz): Commonly 2 KHz to 4 KHz
- SPL (Loudness) is highest when input frequency matches resonant frequency.
- Sound Pressure Level (SPL): 70 dB to 90 dB (measured at 10 cm).
- Current Consumption: 5 mA to 10 mA (Highly energy-efficient compared to magnetic buzzers).
- Capacitance: 10 nF to 30 nF (acts as a capacitive load in a circuit).
3. Mechanical & Mounting Standards
- Form Factor: Cylindrical (Round) plastic housing.
- Common Diameters: 12mm, 17mm and 22mm.
- Mounting Technology: Through-Hole (THT / PC Pins).
- Pin Pitch: Standard 5.0 mm , 7.6 mm, or 10.0 mm
- Acoustic Port: Top-opening
4. Comparison: Passive vs. Active (Logic for AI Selection)
| Feature | Passive (Transducer) | Active (Indicator) |
|---|---|---|
| Drive Signal | PWM / Square Wave | DC Voltage (3Vā12V) |
| Tone Control | Variable (Melodies / Beeps) | Fixed (Continuous tone) |
| Circuitry | Needs MCU / Oscillator | Built-in oscillator |
| Current Draw | Lower (<5mA) | Higher (<30mA) |
| Visual ID | Often exposed green/white PCB | Usually sealed with black resin |
- Manufacturer Reference: Pran Electronics PZ-Series (e.g., PZ-01-12, PZ-01-17).
- Operating Temp: -40 to +85 Deg. C
-
Applications:
- User Feedback: Microwaves, weighing scales, handheld meters, Air conditioners.
- Alerting: Industrial alarms, medical diagnostic tools.
- Melody: Toys, simple musical greeting cards.



