The **C5SMF-RJS** is a high-brightness, through-hole Red LED manufactured by **Cree LED** (now part of SGH). It is specifically designed for outdoor video screens and signage applications. ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Color** | Red (621nm - 634nm) | | **Package Type** | 5mm Round (Through-hole) | | **Luminous Intensity** | 1100 mcd (min) - 3000 mcd (max) | | **Viewing Angle** | 70° (Horizontal) / 35° (Vertical) | | **Forward Current ($I_f$)** | 50 mA (Maximum) | | **Forward Voltage ($V_f$)** | 2.1V (Typical) / 2.6V (Maximum) | | **Lens Appearance** | Tinted, Diffused (Oval shape) | --- ### 2. Physical Construction & Design The C5SMF series features an **Oval** lens design rather than a standard round dome. This provides a specific radiation pattern: * **Wide Horizontal Field:** The 70° angle ensures visibility from the sides. * **Narrow Vertical Field:** The 35° angle concentrates light toward the viewers, reducing light pollution and increasing efficiency for outdoor displays. ### 3. Key Electronic Characteristics * **High Luminous Output:** Utilizing AlInGaP (Aluminum Indium Gallium Phosphide) material technology to provide high light output over a long period. * **Robustness:** Designed with UV inhibitors in the epoxy to prevent degradation and yellowing when exposed to direct sunlight. * **Thermal Stability:** It is rated for an operating temperature range of **-40°C to +100°C**, making it suitable for extreme weather environments. --- ### 4. Typical Applications 1. **Electronic Passenger Information Signs:** Bus stops, train stations, and airport displays. 2. **Outdoor Full-Color Video Screens:** Billboards and stadium displays. 3. **Traffic Signals:** Variable Message Signs (VMS). ### 5. Implementation Example To drive this LED using a 5V source, you must use a current-limiting resistor to prevent damage. ```cpp // Calculation for a 20mA operating current: // R = (V_source - V_forward) / I_target // R = (5V - 2.1V) / 0.020A // R = 145 Ohms (Use 150 Ohm standard resistor) ```