The **KRTB-2A11-R** is a high-performance, surface-mount (SMD) **RGB (Red, Green, Blue) LED** manufactured by **Kingbright**. It belongs to the "Tri-Color" family and is designed for applications requiring high-density spacing and vibrant color mixing. --- ### 1. General Specifications The KRTB-2A11-R features three independent LED chips (Red, Green, and Blue) housed within a single ultra-compact package. | Feature | Specification | | :--- | :--- | | **Package Type** | PLCC-4 / SMD | | **Dimensions** | 2.1mm x 2.1mm x 1.0mm | | **Common Terminal** | Common Anode | | **Lens Type** | Water Clear / Black Surface (for high contrast) | | **Viewing Angle** | 120° | --- ### 2. Optical Characteristics (Typical) Each color channel has specific intensity and wavelength properties. | Color | Peak Wavelength ($\lambda p$) | Luminous Intensity ($I_v$) | | :--- | :--- | :--- | | **Red** | 630 nm | 120 - 250 mcd | | **Green** | 520 nm | 280 - 550 mcd | | **Blue** | 465 nm | 60 - 150 mcd | --- ### 3. Electrical Parameters To operate the LED safely, you must manage the Forward Voltage ($V_F$) and Forward Current ($I_F$). | Parameter | Red | Green | Blue | | :--- | :--- | :--- | :--- | | **Forward Voltage ($V_F$)** | 2.0V | 3.2V | 3.2V | | **Forward Current ($I_F$)** | 20mA | 20mA | 20mA | | **Power Dissipation** | 75mW | 102mW | 102mW | --- ### 4. Application and Usage Because this component is a **Common Anode** device, the wiring logic is as follows: * **Pin 4 (Common Anode):** Connect to the positive voltage source ($V_{CC}$). * **Pins 1, 2, 3 (Cathodes):** Connect to ground through current-limiting resistors or a PWM controller (transistor/IC) to control brightness. #### Example: Calculating Resistor Values If using a 5V supply and wanting 20mA current: ```python # Formula: R = (V_supply - V_forward) / I_forward R_red = (5.0 - 2.0) / 0.020 # 150 Ohms R_green = (5.0 - 3.2) / 0.020 # 90 Ohms R_blue = (5.0 - 3.2) / 0.020 # 90 Ohms ``` --- ### 5. Key Advantages * **High Contrast:** The black package surface reduces reflections, making it ideal for indoor video walls and signage. * **Wide Viewing Angle:** The 120-degree dispersion ensures color consistency even when viewed from the side. * **Compact Footprint:** Perfect for "mini-LED" style displays where pixels must be placed very close together.