Based on electronic component specifications, the **A2L3-R** (often associated with high-power LED series, specifically from manufacturers like *Lite-On* or *Lumileds*) is a surface-mount device (SMD) often used in signaling and lighting applications. Below is a breakdown of its technical characteristics and electronic properties. --- ### 1. Key Technical Specifications The "A2L3-R" typically refers to an AllnGaP (Aluminum Indium Gallium Phosphide) Red LED. | Parameter | Typical Value | | :--- | :--- | | **Material** | AlInGaP | | **Color** | Red (620nm - 635nm) | | **Forward Voltage ($V_F$)** | 2.1V - 2.4V | | **Forward Current ($I_F$)** | 350mA - 700mA (High Power) | | **Luminous Flux** | 40 - 60 Lumens (at 350mA) | | **Viewing Angle** | 120° to 140° | | **Package Type** | Power LED (SMD) | --- ### 2. Internal Electronic Structure The part functions as a high-efficiency semiconductor diode. Here is how the internal electronics are structured: * **P-N Junction:** Uses a high-performance **AlInGaP** chip. This material is chosen for red LEDs because it offers high efficiency and low thermal resistance compared to older GaAsP technologies. * **Thermal Pad:** Unlike standard 5mm LEDs, the A2L3-R features an electrically isolated thermal pad on the bottom. This allows for heat dissipation directly into the PCB without shorting the anode or cathode. * **ESD Protection:** Many variants include a Zener diode wired in parallel (reverse bias) to protect the sensitive LED chip from Electrostatic Discharge (ESD) spikes. --- ### 3. Application Circuitry When designing a circuit for this part, a constant current driver is required rather than a simple voltage source to prevent thermal runaway. #### Example Calculation (Linear Drive) To drive the A2L3-R from a 5V source at 350mA: ```python # Ohms Law: R = (V_source - V_forward) / I_forward v_source = 5.0 # Volts v_forward = 2.2 # Volts (typical for Red) i_forward = 0.35 # Amperes (350mA) resistor_value = (v_source - v_forward) / i_forward # Result: 8.0 ohms ``` --- ### 4. Implementation Guidelines 1. **Heat Management:** Because this is a high-power part, it requires an **MCPCB (Metal Core Printed Circuit Board)** or significant copper pours to act as a heatsink. 2. **Polarity:** The cathode is usually marked by a notch on the lead frame or a specific mark on the underside of the package. 3. **Reflow Soldering:** Must follow the JEDEC J-STD-020 standard for lead-free soldering profiles to avoid damaging the internal bonding wires.