The **KRTB-2CA-R** is a specific surface-mount (SMD) Light Emitting Diode (LED) manufactured by **ROHM Semiconductor**. It is a high-performance RGB (Red, Green, Blue) LED designed for high-density mounting and color mixing applications. --- ### 1. Key Technical Specifications The following table outlines the primary electrical and optical characteristics of the KRTB-2CA-R: | Parameter | Red (R) | Green (G) | Blue (B) | |:---|:---|:---|:---| | **Material** | AlGaInP | InGaN | InGaN | | **Wavelength (typ.)** | 624 nm | 527 nm | 470 nm | | **Luminous Intensity** | 350 mcd | 800 mcd | 160 mcd | | **Forward Voltage ($V_F$)** | 2.1 V | 3.3 V | 3.3 V | | **Max Forward Current** | 25 mA | 25 mA | 25 mA | | **Operating Temp** | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | --- ### 2. Physical Construction * **Package Size:** 1010 (1.0mm x 1.0mm). This is an ultra-compact "Picoled" form factor. * **Configuration:** Common Anode. The positive terminals of the three internal chips are tied together, while the cathodes (negative) are controlled independently. * **Surface Finish:** Black peripheral coloring to improve contrast ratios in display applications. --- ### 3. Electronic Design Considerations #### Power Dissipation When driving all three colors simultaneously to achieve white light, thermal management is critical. The total power dissipation ($P_D$) must not exceed the package limits (typically around 74mW at room temperature). #### Current Limiting Because LEDs are current-driven devices, each cathode (R, G, and B) requires a dedicated series resistor or a constant-current LED driver channel to prevent thermal runaway. #### PWM Dimming To achieve a full spectrum of colors (16.7 million colors), the KRTB-2CA-R is typically driven using **Pulse Width Modulation (PWM)**. By varying the duty cycle of each color's cathode connection, you can adjust the perceived brightness and blend the colors precisely. --- ### 4. Common Applications Due to its small footprint and high intensity, this part is commonly used in: * **Indoor Full-color Displays:** High-resolution LED video walls. * **Indicator Lights:** Status indicators for portable electronics (smartphones, wearables). * **Backlighting:** Small control panels or automotive dashboards where space is at a premium.