The **LSMT2-20061-R** is a high-performance, surface-mount (SMD) piezoelectric transducer (buzzer) commonly used in consumer electronics for audio signaling. It is designed to provide clear sound output while maintaining a very low profile. ### Technical Specifications | Parameter | Value / Range | | :--- | :--- | | **Type** | Piezoelectric Transducer | | **Rated Voltage** | 3.0 Vp-p | | **Operating Voltage** | 1.0 ~ 25.0 Vp-p | | **Current Consumption** | Max 3mA at 3.0 Vp-p / 4.0 kHz | | **Sound Pressure Level (SPL)** | Min 75dB (at 10cm, 3.0 Vp-p, 4.0 kHz) | | **Resonant Frequency** | 4,000 Hz ± 500 Hz | | **Operating Temperature** | -40°C to +85°C | | **Mounting Type** | Surface Mount (SMD) | --- ### Key Features and Construction 1. **Piezoelectric Element:** Unlike magnetic buzzers that use a coil and magnet, this part uses a ceramic disc that deforms when voltage is applied. This results in much lower power consumption and zero electromagnetic interference (EMI). 2. **External Drive Circuitry:** Note that this is a **transducer**, not an indicator. It does not have an internal oscillation circuit. You must provide a square wave signal (typically 4.0 kHz) from a microcontroller or timer IC to produce sound. 3. **Reflow Solder Compatible:** The housing material is typically high-temperature plastic (LCP), allowing it to go through standard industrial reflow soldering processes without melting. 4. **Compact Footprint:** The "2006" in the part number often refers to the approximate dimensions (e.g., ~12mm x 12mm or smaller depending on the specific manufacturer's naming convention; typically around 9mm for this series). --- ### Application Circuit Example To drive the LSMT2-20061-R using a 3.3V or 5V microcontroller, a simple transistor switching circuit is recommended to protect the MCU pins from capacitive kickback. ```cpp // Example Arduino Code Snippet to drive the buzzer const int buzzerPin = 9; // Connect to Base of NPN transistor void setup() { pinMode(buzzerPin, OUTPUT); } void loop() { // Generate a 4kHz tone (the resonant frequency) tone(buzzerPin, 4000); delay(500); noTone(buzzerPin); delay(1000); } ``` --- ### Common Use Cases * **Handheld Devices:** POS terminals, glucose meters, and scanners. * **Household Appliances:** Microwave beepers or control panel feedback. * **Security Systems:** Keypad entry confirmation sounds.