The **C4SMA-RGY** is a high-brightness, through-hole LED manufactured by **Cree LED (Wolfspeed)**. It is specifically designed for outdoor video screens, signage, and decorative lighting. --- ### 1. General Specifications The part number follows a specific nomenclature used by Cree for their High-Brightness LED line. | Parameter | Specification | | :--- | :--- | | **Color** | Red | | **Package Type** | 4mm Oval (Through-hole) | | **Lens Appearance** | Tinted / Diffused | | **Dominant Wavelength** | 619nm - 624nm | | **Luminous Intensity** | 390 mcd - 1100 mcd | | **Viewing Angle** | 105° (Horizontal) / 45° (Vertical) | --- ### 2. Key Electronic Characteristics These parameters are critical for circuit design and power management. * **Forward Voltage ($V_F$):** Typically **2.1V** (Maximum 2.6V). * **Forward Current ($I_F$):** Recommended at **20mA**. * **Reverse Voltage ($V_R$):** 5V maximum. * **Power Dissipation ($P_D$):** Approximately 52mW. * **Operating Temperature:** -40°C to +100°C. --- ### 3. Physical Features & Design The C4SMA series is engineered for outdoor durability and specific optical performance: 1. **Oval Shape:** The 4mm oval design is intentional. It provides a **wide horizontal viewing angle** and a **narrow vertical viewing angle**, which is the industry standard for large-scale outdoor LED billboards (minimizing light wasted towards the sky). 2. **UV Resistance:** The epoxy resin contains UV inhibitors to prevent yellowing or degradation when exposed to direct sunlight for long periods. 3. **Standoffs:** The leads often come with "stoppers" or standoffs to ensure consistent mounting height on the PCB. --- ### 4. Typical Applications * **Full-Color Video Screens:** Used as the "Red" component in an RGB pixel. * **Variable Message Signs (VMS):** Highway traffic signs and information boards. * **Amusement Lighting:** Theme park displays and decorative lighting. * **Commercial Signage:** Gas station price displays and digital billboards. --- ### 5. Implementation Example (Basic Calculation) To drive this LED from a 5V DC source at the standard 20mA: ```python # Ohms Law: R = (V_source - V_forward) / I_forward v_source = 5.0 v_forward = 2.1 i_forward = 0.020 resistor_value = (v_source - v_forward) / i_forward print(f"Required Resistor: {resistor_value} Ohms") # Result: 145 Ohms ```