Spring-Loaded Piezoelectric Passive Buzzer with Pogo Pin

The Spring-Loaded Piezoelectric Passive Buzzer with Pogo Pin is a through‑hole piezoelectric passive buzzer engineered for applications where PCB z‑axis clearance is the primary mechanical constraint. At just 5.5 mm tall and 0.60 g, it offers the same acoustic output (83–86 dB at 4000 Hz) as taller 7.0 mm variants, while fitting into sub‑6 mm total assembly envelopes — including PCB thickness, solder joints, and housing clearance.

Manufactured in MEIDI’s ISO‑9001 certified Jiangsu facility, this component leverages a precisely tuned ceramic diaphragm and optimised internal cavity to maintain resonant efficiency despite the reduced height. Its 1–30 V ultra‑wide operating range eliminates the need for voltage‑specific SKUs, simplifying BOM management across 3.3 V, 5 V, 12 V, and 24 V product lines. With measured current consumption of just 0.63–0.78 mA at 5 Vp‑p, it delivers a 40‑to‑60× reduction in power draw compared to electromagnetic alternatives, making it ideal for battery‑powered wearables, portable medical devices, and IoT sensors.

Core Engineering Advantages

5.5 mm ultra‑slim profile – 21% height reduction compared to 7.0 mm alternatives; enables sub‑6 mm total z‑axis assemblies including PCB and solder

Acoustic performance parity – 83–86 dB at 4000 Hz matches thicker variants; no SPL penalty for slim form factor

1–30 V ultra‑wide operating range – single SKU replaces voltage‑specific buzzers across 3.3 V, 5 V, 12 V, and 24 V systems

12 nF capacitive load – direct MCU GPIO drive in most applications; slightly higher capacitance than 10 nF variants for marginally louder output at same voltage

0.60 g ultra‑light mass – 9% lighter than 0.66 g alternatives; minimises inertial loading in wearable and portable designs

Through‑hole polarized mounting – mechanical retention and polarity protection in industrial and automotive installations

Application Environments – Where Height Matters

Wearable health devices – fitness tracker goal alerts, smartwatch notification tones, and hearable device pairing chimes where 6 mm total thickness is the wearable limit

Ultra‑thin IoT sensor nodes – environmental threshold warnings, tamper alerts, and connectivity status tones in sub‑10 mm total device thickness

Portable medical instruments – digital thermometer fever alerts, pulse oximeter limit tones, and portable ECG completion beeps in pocket‑sized devices

Smart card and token devices – transaction confirmation tones, PIN entry feedback, and battery‑low warnings in credit‑card‑form‑factor security devices

Automotive 12 V/24 V interior modules – seatbelt reminders, key‑in‑ignition chimes, and diagnostic tool feedback without voltage regulator overhead

Industrial 24 V control panels – fault indication, cycle‑completion tones, and limit‑switch alerts in PLC and relay‑logic systems

Manufacturing Excellence – Quality Assurance from MEIDI

MEIDI produces the HNR‑1255 PA5.0 on dedicated piezoelectric assembly lines with automated ceramic pressing, electrode firing, and housing encapsulation. Our Jiangsu manufacturing base operates under ISO 9001:2015 quality management, with statistical process control at every stage – from raw material inspection to final acoustic verification.

Each production lot undergoes comprehensive qualification:

Capacitance 100% test – 12 nF ±40% verification at 1 kHz; measured range 11.7–14.2 nF ensures consistent driver matching

Resonant frequency sampling – 4000 Hz ±12.5% statistical verification; typical measured range 3900–4080 Hz

SPL batch verification – ≥80 dB minimum at 5 Vp‑p, 4000 Hz; sample range 83–86 dB confirms acoustic consistency

Current consumption validation – ≤10 mA maximum; measured 0.63–0.78 mA confirms sub‑milliampere efficiency

High‑temperature storage – 48 hours at +80 ± 2 ℃; parameter recovery after 2‑hour ambient stabilisation

Low‑temperature storage – 48 hours at -30 ± 2 ℃; verified activation at 1 V minimum

Thermal shock cycling – 5 cycles between -30 ℃ and +80 ℃ with 30‑minute dwell per extreme

Mechanical stress validation – sinusoidal vibration (10–55 Hz, 1.0 mm amplitude, XYZ axes, 0.5 hours cumulative) and 75 cm free‑fall drop onto 10 mm hardwood (3 impacts)

Humidity resistance – 48 hours at 50 ± 5 ℃ / 90–95% RH followed by 2‑hour recovery and electrical characterisation

Solder heat resistance – 250 ± 5 ℃ for 10 ± 0.5 seconds with 2.0 mm body‑to‑solder clearance

All components are RoHS, REACH, and UL94 V‑0 compliant. Lot code markings on each unit enable 10‑year traceability to production date, test data, and raw material certificates.

Engineering FAQ – Practical Insights for Designers

Q1: How does the 5.5 mm height affect acoustic output compared to the 7.0 mm HNR‑1207 PA6.5?

Acoustic output is equivalent. Both models deliver 83–86 dB at 4000 Hz and 5 Vp‑p. The HNR‑1255 PA5.0 achieves this through optimised internal cavity geometry and ceramic element tuning that maintains resonant efficiency despite the reduced height. The trade‑off is a slightly higher capacitance (12 nF vs. 10 nF) and marginally increased current draw (0.63–0.78 mA vs. 0.45–0.54 mA) – both still sub‑milliampere and negligible in practice. For designs where 7.0 mm fits, either model performs identically. For sub‑6 mm z‑axis constraints, only the 5.5 mm variant qualifies.

Q2: Can the HNR‑1255 PA5.0 replace the HNR‑1207 PA6.5 in an existing design without circuit modification?

Yes, with minor verification. Both share identical 12.5 mm diameter, 1–30 V range, 4000 Hz resonance, and through‑hole pin configuration. The 12 nF capacitance (vs. 10 nF) increases drive current by approximately 20% at the same voltage and frequency – from 0.5 mA to 0.6 mA typical. This is well within the capability of any MCU GPIO or driver circuit already designed for the HNR‑1207. Verify PCB keepout zones: the 5.5 mm height may reduce required z‑axis clearance, potentially allowing denser component stacking above the buzzer.

Q3: What is the minimum drive voltage for audible output in a 3.3 V coin‑cell design?

Approximately 1.5–2.0 Vp‑p produces faint but perceptible output in quiet environments. At 3.3 Vp‑p and 4000 Hz, expect 70–75 dB – adequate for proximity alerts, button feedback, and status tones in consumer devices. The ≥80 dB specification is validated at 5 Vp‑p; 3.3 V operation yields proportionally lower SPL. For battery‑critical designs, the sub‑milliampere draw means even a CR2032 coin cell (220 mAh) sustains 300 000+ hours of intermittent tone operation.

Q4: How does the 12 nF capacitance affect driver circuit selection compared to 10 nF alternatives?

At 4000 Hz, the capacitive reactance is approximately 3.3 kΩ for 12 nF (vs. 4.0 kΩ for 10 nF). This marginally higher load current is still well within standard MCU GPIO sourcing limits (typically 8–20 mA). For dedicated piezo driver ICs, the 12 nF load is comfortably within specification. The higher capacitance can actually be advantageous: at the same drive voltage, slightly more energy transfers to the ceramic element, contributing to the acoustic output parity with taller variants despite the reduced cavity volume.

Q5: Is the HNR‑1255 PA5.0 suitable for continuous‑tone 24 V industrial applications?

Yes, with appropriate drive circuit design. The capacitive nature means current remains self‑limiting by reactance – approximately 1.8 mA RMS at 24 Vp‑p and 4000 Hz. However, a series damping resistor (100–330 Ω) is recommended to suppress ringing and protect the driving transistor from reactive load transients. Ensure the drive circuit withstands 24 V levels; standard 3.3 V or 5 V MCU pins require a level‑shifting MOSFET or optocoupler. For continuous‑tone duty, the negligible current draw produces minimal driver heating even at 24 V.

Q6: Can this buzzer be used in high‑humidity environments such as marine or outdoor applications?

The standard HNR‑1255 PA5.0 is not hermetically sealed and is rated for 90–95% RH non‑condensing environments per the humidity resistance test (48 h at 50 °C / 95% RH). For continuous outdoor or marine exposure, MEIDI offers conformal coating or encapsulation as a custom option. Contact our engineering team to discuss ingress protection requirements and available modifications.