The **LPD-23PA-R** is a high-performance, ultra-low profile piezoelectric buzzer (transducer) manufactured by **Kingstate Electronics**. It is widely used in compact consumer electronics where space is a premium but clear sound notification is required. --- ### ## Technical Specifications The following table outlines the primary electrical and physical characteristics of the LPD-23PA-R: | Parameter | Specification | | :--- | :--- | | **Type** | Piezoelectric Transducer (External Drive) | | **Operating Voltage** | 1.0 ~ 25 Vp-p | | **Rated Voltage** | 3.0 Vp-p | | **Sound Pressure Level (SPL)** | Min. 70 dB at 10cm (at 3.0 Vp-p / 4.0 kHz) | | **Current Consumption** | Max. 3 mA at 3.0 Vp-p | | **Resonant Frequency** | 4,000 Hz ± 500 Hz | | **Capacitance** | 12,000 pF ± 30% (at 120 Hz) | | **Operating Temperature** | -20°C to +70°C | | **Mounting Type** | Surface Mount Device (SMD) | --- ### ## Key Electronic Components & Materials The LPD-23PA-R is an "External Drive" type, meaning it does not have internal oscillation circuitry. It functions as a capacitive load. 1. **Piezoelectric Ceramic Element:** The core of the device. When an AC voltage is applied, the ceramic expands and contracts (the inverse piezoelectric effect), creating sound waves. 2. **Metal Diaphragm:** A thin brass or stainless steel plate attached to the ceramic. It acts as a resonator to amplify the vibrations into audible sound. 3. **Housing Case:** Made of LCP (Liquid Crystal Polymer) or high-temperature plastic, designed to withstand the heat of **Reflow Soldering**. 4. **Terminals:** Gold-plated pads located on the bottom for SMD integration onto a PCB. --- ### ## Driving Circuit Example Since this is a transducer (not an indicator), you must provide a square wave at the resonant frequency (4.0 kHz) to produce sound. ```cpp // Example: Driving LPD-23PA-R with an Arduino (PWM) int buzzerPin = 9; // Connect to a transistor driving the buzzer void setup() { pinMode(buzzerPin, OUTPUT); } void loop() { tone(buzzerPin, 4000); // Send a 4kHz signal delay(500); // Sound for 500ms noTone(buzzerPin); // Stop delay(1000); // Wait 1 second } ``` --- ### ## Usage Considerations * **Polarity:** Piezo transducers are typically non-polarized, but it is best practice to follow the PCB footprint markings for optimal acoustic performance. * **Drive Circuit:** Because it acts like a capacitor, it is recommended to use a **transistor (BJT or MOSFET)** or a dedicated buzzer driver IC rather than driving it directly from a low-power microcontroller pin. * **Acoustic Hole:** Ensure the sound emission hole on the top of the casing is not obstructed by other components or the device enclosure.