The **LSMT2-34550-R** is a high-performance, surface-mount (SMT) magnetic transducer (buzzer) commonly used in consumer electronics, medical devices, and industrial alarms. It is designed to provide clear audio feedback in a compact footprint. --- ### 1. Key Technical Specifications Below are the primary electrical and physical characteristics of the component: | Feature | Specification | | :--- | :--- | | **Type** | Magnetic Transducer (External Drive) | | **Rated Voltage** | 3.0 Vo-p | | **Operating Voltage** | 2.0 ~ 5.0 Vo-p | | **Current Consumption** | Max 80 mA | | **Sound Pressure Level (SPL)** | Min 85 dB @ 10cm | | **Resonant Frequency** | 2730 Hz | | **Coil Resistance** | 15 ± 3 Ω | | **Operating Temperature** | -40°C to +85°C | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Operational Mechanism The LSMT2-34550-R is a **transducer**, not an indicator. This means it does not have internal circuitry to generate a tone. * **Driving Circuit:** It requires an external square wave signal at its resonant frequency (approx. 2700 Hz) to produce sound. * **Inductive Load:** Because it uses a voice coil and magnet, it acts as an inductive load. A flyback diode is often recommended in the drive circuit to protect the controlling transistor or MCU from voltage spikes. --- ### 3. Application Circuit Example To drive this component using a microcontroller (MCU), a simple NPN transistor switching circuit is typically used: ```cpp // Logic Diagram for driving the LSMT2-34550-R // VCC (3.0V - 5.0V) // | // [Buzzer +] // [Buzzer -] ----+---- [Collector of NPN Transistor] // | // [Diode] (Cathode to VCC, Anode to Collector) // | // [MCU Pin] --[Resistor]-- [Base of NPN] // [Emitter to Ground] ``` --- ### 4. Physical Dimensions and Material * **Housing:** High-temperature plastic (LCP), capable of withstanding lead-free reflow soldering processes. * **Size:** Compact square or rectangular form factor (typically around 5mm - 9mm, depending on the specific series revision). * **Polarity:** The device is polarized; the positive (+) terminal must be oriented correctly according to the PCB footprint. ---