The **C5SMF-RJF** is a high-performance, through-hole LED manufactured by **Cree LED** (formerly Wolfspeed/Cree). It belongs to the **Screen Master** family, specifically designed for outdoor electronic signs and signals. --- ### 1. General Specifications The C5SMF-RJF is a **4mm Oval LED**. Its oval shape is engineered to provide a wide horizontal viewing angle and a narrow vertical viewing angle, making it ideal for outdoor displays where viewers are positioned at various side angles but not significantly above or below the screen. | Parameter | Specification | | :--- | :--- | | **Color** | Red | | **Dominant Wavelength** | 619 nm - 624 nm | | **Luminous Intensity** | 1100 - 3000 mcd (millicandela) | | **Viewing Angle** | 100° (Horizontal) / 45° (Vertical) | | **Lens Appearance** | Red Diffused | | **Package Type** | Through-hole (Radial) | --- ### 2. Electrical Characteristics Understanding the electrical requirements is critical for circuit design (selecting resistors and power supplies). | Characteristic | Typical Value | Maximum Rating | | :--- | :--- | :--- | | **Forward Current ($I_F$)** | 20 mA | 50 mA | | **Forward Voltage ($V_F$)** | 2.1 V | 2.6 V | | **Reverse Voltage ($V_R$)** | - | 5 V | | **Power Dissipation** | - | 130 mW | | **Operating Temperature** | -40°C to +100°C | - | --- ### 3. Key Physical Features * **Oval Shape:** The 4mm oval lens is optimized for "Full Color Video" and "Message Signs." * **Standoffs:** The "F" in the part number often denotes the lead frame style. These LEDs usually come with **standoffs** (small protrusions on the leads) to ensure consistent spacing from the PCB during soldering and to allow for better heat dissipation. * **UV Resistance:** The epoxy contains UV inhibitors to prevent the lens from yellowing or becoming brittle when exposed to direct sunlight for extended periods. --- ### 4. Common Applications Due to its high brightness and specific viewing angles, this part is used in: 1. **Variable Message Signs (VMS):** Highway traffic signs. 2. **Outdoor Video Screens:** Large-scale advertising billboards. 3. **Petrol Station Signs:** Digital price displays. 4. **Amusement Signage:** High-visibility park directions or ride signs. --- ### 5. Design Considerations * **Current Limiting:** Always use a series resistor to prevent thermal runaway. * *Calculation Example:* To run at 20mA on a 5V supply: $R = (5V - 2.1V) / 0.02A = 145 \Omega$. * **Thermal Management:** For high-density displays, ensure adequate airflow, as heat can shift the wavelength (color) and reduce the lifespan of the LED.