The **ALR-641-R** is a specific electronic component, typically categorized as a **Surface Mount Device (SMD) LED**, often utilized in signal indicators, automotive lighting, and consumer electronics. Below is a breakdown of its technical specifications and electronic characteristics. --- ### 1. Technical Specifications The "ALR-641-R" usually refers to a Red LED in a specific package (often 1206 or similar PLCC formats depending on the manufacturer). | Parameter | Typical Value | Unit | | :--- | :--- | :--- | | **Color** | Red | - | | **Forward Voltage ($V_f$)** | 1.8V - 2.4V | Volts | | **Forward Current ($I_f$)** | 20mA (Max 30mA) | Milliamps | | **Peak Wavelength** | 630nm - 640nm | Nanometers | | **Luminous Intensity** | 50 - 150 mcd | Millicandela | | **Operating Temperature**| -40°C to +85°C | Celsius | --- ### 2. Internal Electronic Components While an LED is a single semiconductor diode, the ALR-641-R assembly consists of several sub-parts: * **Semiconductor Die:** The "heart" of the component, usually made of **AlGaInP** (Aluminum Gallium Indium Phosphide) for high-brightness red light. * **Lead Frame:** The metal structure that provides mechanical support and electrical conductivity to the PCB pads. * **Encapsulant:** A clear or tinted epoxy/silicone resin that protects the die and shapes the light beam. * **Wire Bond:** A microscopic gold wire connecting the top of the semiconductor die to the negative/positive terminal. --- ### 3. Implementation Circuitry To use this part safely, a current-limiting resistor is required to prevent "thermal runaway." **Basic Calculation Code (Python):** ```python # Calculate Resistor value for ALR-641-R v_source = 5.0 # Supply voltage v_forward = 2.0 # Typical voltage for ALR-641-R i_target = 0.02 # 20mA target current def calculate_resistor(v_s, v_f, i): return (v_s - v_f) / i resistance = calculate_resistor(v_source, v_forward, i_target) print(f"Required Resistor: {resistance} Ohms") ``` --- ### 4. Key Application Areas 1. **Status Indicators:** Power-on lights for routers, laptops, or industrial panels. 2. **Backlighting:** Illuminating membrane switches and LCD displays. 3. **Automotive:** Interior dashboard lighting and button illumination.