The **S4SMS-RJF** is a high-brightness, surface-mount (SMD) LED manufactured by **Cree LED** (specifically within the Screen Master® series). It is primarily designed for high-resolution outdoor video screens and signage applications. --- ### 1. Key Technical Specifications The following table highlights the critical electrical and optical parameters for the S4SMS-RJF: | Parameter | Specification | | :--- | :--- | | **Type** | Single-color SMD LED | | **Color** | Red (typically 621nm wavelength) | | **Luminous Intensity** | 450 - 1120 mcd (millicandela) | | **Viewing Angle** | 120° Horizontal / 60° Vertical (Oval shape) | | **Forward Current ($I_F$)** | 20 mA (nominal) | | **Forward Voltage ($V_F$)** | 2.0V - 2.6V | | **Operating Temp** | -40°C to +85°C | | **Package Size** | 3.2 x 2.8 mm (PLCC4) | --- ### 2. Physical and Design Characteristics * **Oval Beam Pattern:** Unlike standard LEDs that project a circular beam, the S4SMS-RJF has an oval radiation pattern. This is intentional for outdoor signage, as it ensures wide horizontal visibility for pedestrians/drivers while minimizing light waste toward the sky or ground. * **Encapsulation:** The part is usually encapsulated with a UV-resistant epoxy to prevent degradation and yellowing when exposed to direct sunlight for long periods. * **Lead Frame:** It utilizes a PLCC4 (Plastic Leaded Chip Carrier) package, which provides stable soldering points and effective heat dissipation. ### 3. Usage and Application This specific electronic part is commonly found in: 1. **Full-Color Video Displays:** Used in conjunction with Green and Blue SMD LEDs to create high-definition outdoor "Jumbotrons." 2. **Variable Message Signs (VMS):** Traffic signals and highway information boards. 3. **Architectural Lighting:** Accent lighting where high durability and specific viewing angles are required. --- ### 4. Comparison to Other LEDs The "RJF" suffix identifies a specific binning and color range within the S4SMS family. While standard 5mm through-hole LEDs were once the norm for signs, the SMD nature of the S4SMS-RJF allows for: * **Higher Pixel Density:** P10, P8, or even P6 outdoor screens. * **Automated Assembly:** Compatible with high-speed Pick-and-Place SMT machines. * **Improved Contrast:** The black-face surface of some sub-variants helps improve the contrast ratio of the screen in bright daylight.