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True SMD Package for Automated Pick-and-Place — 3 soldering pads (2 polarity + 1 dummy for anti-misorientation) on a 5.0 × 5.2 mm body; compatible with standard SMT feeders and reflow profiles.
Heat-Resistant Black LCP Housing — liquid crystal polymer body withstands reflow peak temperatures up to 260 °C without warping, cracking or outgassing.
Tiny 5 × 5 × 2.5 mm Footprint, 0.1 g Weight — fits inside smartwatch casings, TWS lids, USB dongles and handheld scanners without compromising thinness or balance.
Passive Magnetic Drive, 4000 Hz Resonant Frequency — drive with a 50%-duty square wave at 4000 Hz to reach full output; magnetic construction delivers warmer, more penetrating tone than piezo at low voltage.
≥75 dB SPL at 10 cm — clearly audible in office and low-noise environments despite the miniature size.
Low Operating Voltage 2.5–4.5 Vp-p — direct drive from 3 V MCU GPIO or 1.5 V battery systems with simple transistor/MOSFET stage.
Tin-Plated Brass Terminals — excellent solderability, consistent coplanarity, no tombstoning in reflow.
Tape & Reel Packaging Available — high-volume OEM production ready.
Parameter | Specification |
|---|---|
Brand | TAT |
Model | BM5025SZ-0340-12 |
Buzzer Type | Passive Electromagnetic (Magnetic) SMD Buzzer |
Drive Required | External square wave at resonant frequency |
Rated Voltage | 3.0 Vp-p |
Operating Voltage Range | 2.5 – 4.5 Vp-p |
Resonant Frequency | 4000 Hz |
Rated Current | ≤ 100 mA @ 3.0 Vp-p, 4000 Hz, 50% duty |
Sound Pressure Level | ≥ 75 dB @ 10 cm (at rated conditions) |
Coil Resistance | 12 ± 3 Ω |
Body Dimensions | 5.0 ± 0.2 * 5.2 ± 0.2 mm |
Height | 2.5 mm |
Mounting | SMD, 3 soldering pads (2 polarity + 1 dummy) |
Housing Material | Black LCP (reflow-compatible) |
Terminal Material | Tin-plated brass |
Sound Outlet | Top-side hole |
Net Weight | Approx. 0.1 g |
Operating Temperature | -20 °C ~ +70 °C |
Storage Temperature | -40 °C ~ +85 °C |
Tolerance | ±0.3 mm unless specified |
Certification | RoHS Compliant |
Origin | China |
Measuring conditions: 25±3 °C, 60±10% RH, atmospheric pressure 860–1060 hPa.
Wearables & Hearables — smartwatches, fitness bands, TWS earbud charging cases, key fobs
Mobile Computing — smartphones, tablets, laptops, USB-C docks, SSD enclosures
POS & Handheld — mobile payment terminals, barcode scanners, Bluetooth printers, RFID readers
Smart Home & Security — smart locks, touch keypads, door contact sensors, thermostat alarms
Medical & Health — glucose meters, pulse oximeters, wearable ECG patches
Automotive & IoT — OBD dongles, TPMS sensors, EV chargers, smart speakers
Consumer & Toys — handheld game consoles, electronic dictionaries, reminder cards
Built for Real SMT Lines — LCP housing and tin-plated brass pads pass standard lead-free reflow profiles (JEDEC J-STD-020) with no delamination or popcorn effect.
Lower Drive Voltage Than Piezo — magnetic coils draw audible current directly from a 3 V GPIO, eliminating the need for a charge pump or step-up transformer required by piezo buzzers.
Anti-Tombstone, Anti-Misorientation — three-pad layout (two polarized + one dummy) ensures correct placement orientation on the pick-and-place camera.
Tape & Reel, Moisture-Safe Packaging — 7" reels, sealed ESD bags with desiccant, MSL grade suitable for high-volume assembly.
Full OEM/ODM Flexibility — resonant frequency options (2 kHz / 4 kHz / 8 kHz), SPL tuning (70–85 dB), custom reel quantities, and alternative pad layouts available.
Q1: Is this buzzer active or passive? This is a passive magnetic buzzer. You must feed it an external square-wave drive signal at 4000 Hz (50% duty) from an MCU PWM pin or oscillator circuit. Applying DC voltage will not produce sound.
Q2: How do I drive it from an MCU? Connect one pad to a GPIO PWM pin (outputting 4 kHz square wave at 3 V) and the other to GND. For louder output, use an NPN/MOSFET transistor stage or a half-bridge driver. Coil resistance is 12 Ω, so current peaks near 100 mA at 3 V.
Q3: Can it survive reflow soldering? Yes. The housing is black LCP rated for lead-free reflow peak temperatures up to 260 °C. Follow the JEDEC J-STD-020 reflow curve recommended in the datasheet.
Q4: What does the third "dummy" pad do? The dummy pad has no electrical function. It is a mechanical orientation marker that lets the pick-and-place camera and operators identify pin 1 and prevents reverse mounting.
Q5: How loud is it compared to through-hole buzzers? At ≥75 dB SPL measured at 10 cm it is clearly audible in typical office and home environments. It is quieter than larger 9 mm/12 mm through-hole buzzers (which reach 85–95 dB) because of the reduced diaphragm area.
Q6: Do you supply tape & reel packaging? Yes. Standard shipping is tray/tube for samples; volume orders ship tape & reel on 7-inch reels, ESD-shielded and moisture-bagged.
