External signal driven — full PWM frequency control for customized tone generation
Low current consumption, Max. 1mA rated current, suitable for battery-powered devices
Resonant frequency 4000±500Hz for clean, low-harmonic tone output
Compact 6.0x6.0mm footprint for integration into space-constrained equipment
Operating temperature range -20℃ to +70℃, adaptable to various environmental conditions
The MEIDI MTL1325 is a piezoelectric passive buzzer engineered for embedded control systems requiring programmable sound generation with precise frequency control. Unlike active buzzers with fixed oscillators, this passive design accepts external PWM or AC drive signals, enabling engineers to modulate tone frequency, duration, and pattern sequences for application-specific acoustic feedback.
The 4000Hz resonant frequency is factory-tuned with ±500Hz tolerance, ensuring predictable acoustic performance across production lots. The piezoelectric actuator delivers rapid response, making it suitable for time-critical alarm sequences in industrial automation, consumer electronics, and safety interlock systems.
At 6.0x6.0mm, MTL1325 integrates into space-constrained PCB layouts where low harmonic distortion and minimal electromagnetic interference are essential. The -20℃ to +70℃ operating range accommodates equipment subjected to various thermal environments.
| Parameter | Value | Test Conditions |
| Product Type | Piezoelectric Passive Buzzer | — |
| Resonant Frequency | 4000 ± 500 Hz | At rated voltage |
| Operating Voltage | 1 ~ 20 Vp-p | Drive signal range |
| Rated Current | Max.1mA | At 4KHz 50% duty Square Wave 3Vp-p |
| Sound Pressure Level | Min.75dB | At 4KHz 50% duty Square Wave 3Vp-p (10cm distance) |
| Capacitance | 15000 ± 30% pF | At 1KHz |
| Operating Temperature | -20℃ ~ +70℃ | Continuous |
| Storage Temperature | -30℃ ~ +80℃ | Non-operating |
| Net Weight | Approx. 0.5 g | Typical |
| Environmental Compliance | RoHS Compliant | — |
| Housing Material | Black LCP | — |
| Mounting Type | SMD with Spring Contact | — |
Industrial control panels — status indication tones, fault alerts, and operator confirmation feedback
Portable handheld devices — low current consumption audible alert applications
Smart home appliances — cycle completion chimes, door-open warnings, and connectivity status tones in white goods and IoT devices
Test and measurement instruments — calibration prompts, threshold-crossing alerts, and self-test completion indicators
Access control systems — keypad entry confirmation, unauthorized access warnings, and door status notifications
Telecommunications equipment — line status tones, message waiting alerts, and diagnostic feedback in network hardware
| Design Requirement | MTL1325 Advantage |
| Variable tone sequences | External PWM drive enables frequency modulation, unlike fixed-tone active buzzers |
| Fast alarm response | Piezoelectric actuation provides rapid acoustic onset |
| EMC-sensitive environment | Zero magnetic emission; no risk of interference with RF circuits or sensitive electronics |
| Frequency precision | Factory-tuned 4000Hz ±500Hz ensures consistent tone across production batches |
| Low power consumption | Max.1mA current draw at rated drive conditions, suitable for battery-operated designs |
| Spring contact mounting | SMD-compatible spring contact enables reliable electrical connection in modular or test-fixture applications |
1. Does this buzzer require a PWM signal, or can it be driven with a simple DC voltage?
As a passive piezoelectric buzzer, MTL1325 requires an external AC signal — typically a square wave or PWM at or near 4000Hz — to generate audible output. DC voltage alone will not produce sound; the piezoelectric element requires polarity reversal to mechanically flex and generate acoustic pressure.
2. What driving frequency is recommended for maximum sound pressure output?
Maximum SPL occurs at the resonant frequency of 4000Hz. Driving within ±5% of resonance maintains ≥90% of rated output. SPL decreases significantly when driven off resonance.
3. Can the capacitance value vary, and how does this affect my driver circuit design?
Nominal capacitance is 15000pF with ±30% tolerance. The capacitive load determines the current required from the driver. For microcontroller GPIO drive, verify the pin can source the capacitive charging current at your switching frequency. For higher SPL, a dedicated piezo driver IC with built-in charge pump is recommended.
4. What is the recommended reflow soldering profile for this SMD buzzer?
MTL1325 is compatible with standard SMD reflow processes. Contact MEIDI for the complete reflow profile diagram and temperature specifications to ensure post-soldering electrical performance remains within datasheet limits.
5. How does the piezoelectric construction compare to electromagnetic buzzers in terms of long-term reliability?
Piezoelectric buzzers have no moving coil or magnetic components, eliminating wear mechanisms associated with electromagnetic types. The simple structure without electromagnetic coils provides high reliability.
For technical datasheets, drive circuit application notes, frequency sweep characterization data, or OEM configuration discussion, contact MEIDI applications engineering. Custom buzzer solutions including modified resonant frequencies and alternative mounting configurations are available for specialized requirements.
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