The **L135-R47** is a specific part number belonging to the **LUXEON 3535L** series of Light Emitting Diodes (LEDs) manufactured by **Lumileds**. This component is widely used in commercial and industrial lighting due to its high efficacy and compact form factor. --- ### 1. Part Number Breakdown Understanding the nomenclature helps identify the specific characteristics of the diode: | Segment | Code | Description | | :--- | :--- | :--- | | **Series** | L135 | LUXEON 3535L Series (3.5mm x 3.5mm footprint) | | **Color/Type** | R | Red (Specific wavelength range) | | **Wavelength** | 47 | Denotes a specific binning/wavelength characteristic (approx. 620-630nm) | --- ### 2. Key Technical Specifications The "R47" variant specifically targets the **Red** spectrum. Below are the typical electrical and optical characteristics: * **Package Size:** 3.5mm x 3.5mm x 0.8mm (Industry standard 3535). * **Forward Voltage ($V_f$):** Typically 1.9V to 2.4V. * **Forward Current ($I_f$):** Rated for 100mA (nominal), with a maximum pulse current usually around 200mA. * **Dominant Wavelength:** 620nm – 630nm (Red). * **Viewing Angle:** 115° to 120° (wide distribution). * **Operating Temperature:** -40°C to +105°C. --- ### 3. Structural Composition The L135-R47 is built using high-reliability materials designed for longevity: 1. **Lead Frame:** Silver-plated copper alloy for optimal thermal dissipation. 2. **Encapsulant:** High-clarity silicone resin which resists yellowing under UV and heat. 3. **Die Technology:** AlGaInP (Aluminum Gallium Indium Phosphide) for efficient red light emission. --- ### 4. Common Applications Due to its reliability and specific color output, it is commonly found in: * **Signage:** Channel letters and architectural borders. * **Automotive:** Interior ambient lighting and stop lamps. * **Horticulture:** Used in grow lights to provide the red spectrum necessary for photosynthesis. * **Status Indicators:** Industrial control panels and emergency lighting. --- ### 5. Design Considerations * **Thermal Management:** Despite the small size, proper PCB heat-sinking (Metal Core PCB) is required to prevent "color shift" and lumen depreciation. * **Polarity:** The cathode is usually marked by a notch on one corner of the SMD package.