## Overview of the LTRB RASR The **LTRB RASR** is a specialized, high-performance surface-mount (SMD) LED manufactured by **OSRAM Opto Semiconductors**. It is a **4-lead multi-chip LED** designed specifically for high-density displays and video walls. The name typically refers to the **Multi CHIPLED** family, where "LTRB" stands for the colors integrated into the package: **L** (Light Blue/Cyan - optional or variant specific), **T** (True Green), **R** (Red), and **B** (Blue). --- ### 1. Technical Specifications The following table summarizes the key electrical and optical characteristics of the LTRB RASR: | Parameter | Red (R) | True Green (T) | Blue (B) | | :--- | :--- | :--- | :--- | | **Dominant Wavelength** | 623 nm | 530 nm | 470 nm | | **Luminous Intensity** | ~250 mcd | ~500 mcd | ~100 mcd | | **Forward Voltage (Typ)** | 2.0 V | 2.8 V | 2.8 V | | **Max Forward Current** | 15 mA | 15 mA | 15 mA | | **Viewing Angle** | 120° | 120° | 120° | --- ### 2. Key Features * **Compact Package:** It features a very small footprint (approx. 1.0 mm x 1.0 mm or 1.6 mm x 1.6 mm depending on the specific sub-series), making it ideal for high-resolution "Fine Pitch" LED walls. * **Black Surface:** The package often includes a black surface or "black frame" to improve contrast ratios in display applications, preventing light reflection from the environment. * **Common Anode/Cathode:** Typically designed with a shared electrode to reduce the number of traces required on the PCB. * **Long-Term Stability:** Uses Silicone resin encapsulation for better resistance to UV and humidity compared to standard epoxy. --- ### 3. Connection Diagram Concept Since it is a 4-pin device, the internal wiring usually follows this logic: ```text Pin 1: Cathode (Red) Pin 2: Cathode (True Green) Pin 3: Cathode (Blue) Pin 4: Common Anode (+) ``` *(Note: Always verify the specific datasheet for the polarity, as some variants use Common Cathode.)* --- ### 4. Typical Applications 1. **Indoor LED Video Walls:** High-end advertising screens and command center displays. 2. **Consumer Electronics:** Indicator lights where full RGB color mixing is required in a tiny space. 3. **Gaming Peripherals:** RGB lighting for keyboards or mice where "pixel" density is important. ---