The **SMA12VG-CB2-R** is a specific surface-mount (SMD) magnetic buzzer manufactured by **Challenge Electronics**. It is designed for compact electronics requiring reliable audio signaling. --- ### 1. General Specifications This component is an **Electromagnetic Transducer**. Unlike piezo buzzers, magnetic buzzers operate at lower voltages and use an internal coil and magnet to vibrate a diaphragm. | Parameter | Specification | | :--- | :--- | | **Type** | Magnetic (External Drive) | | **Rated Voltage** | 12 Vp-p | | **Operating Voltage** | 8.0 ~ 15.0 Vp-p | | **Rated Current** | Max. 40 mA | | **Sound Pressure Level (SPL)** | Min. 85 dB @ 10cm | | **Resonant Frequency** | 2,400 Hz | | **Coil Resistance** | 140 ± 14 Ω | | **Mounting Type** | Surface Mount (SMD) | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Physical Characteristics The "SMA" prefix typically denotes a Surface Mount Assembly. The design is optimized for automated pick-and-place machinery and reflow soldering. * **Housing Material:** LCP (Liquid Crystal Polymer), high-temperature resistant for soldering. * **Dimensions:** Usually 12mm x 12mm (as indicated by the "12" in the part number). * **Weight:** Approximately 2.0g. * **Termination:** Solder pads on the bottom of the casing. --- ### 3. Drive Circuitry (External Drive) Because this is a **transducer** and not an indicator, it does not have internal oscillation circuitry. You must provide a square wave at the resonant frequency (2,400 Hz) to produce sound. #### Typical Application Circuit ```text VCC (12V) | [ Buzzer ] | [ NPN Transistor (e.g., MMBT2222) ] --- PWM Signal (2.4kHz) | GND ``` --- ### 4. Part Number Breakdown While manufacturer codes vary slightly, the breakdown for this series generally follows: * **SMA:** Surface Mount Assembly (Magnetic Type). * **12:** Size (12mm). * **VG:** Voltage/Generation series. * **CB2:** Specific design Revision/Housing style. * **R:** RoHS Compliant / Tape & Reel Packaging.