The **SML-R1** series (specifically the **SML-R12** series) is a popular line of high-brightness, surface-mount (SMD) LEDs manufactured by **ROHM Semiconductor**. These components are widely used in consumer electronics, automotive interiors, and industrial indicators due to their compact size and reliability. ### 1. Key Technical Specifications The SML-R1 series typically features a standard 0603 (1608 Metric) package size. Below are the general specifications for common variants: | Parameter | Specification | | :--- | :--- | | **Package Size** | 1.6 x 0.8 mm (0603 inch) | | **Height** | 0.8 mm | | **Operating Temperature** | -40°C to +85°C | | **Forward Current ($I_F$)** | 20mA (Standard) | | **Power Dissipation ($P_D$)** | 50mW - 75mW (Color dependent) | | **Luminous Intensity** | Varies by color (e.g., 25mcd for Red) | --- ### 2. Physical Characteristics The "R1" designation refers to the specific mold and frame structure used by ROHM. * **Miniature Footprint:** The 1.6mm x 0.8mm size makes it ideal for high-density PCB designs. * **Lens Construction:** Usually features a clear, flat resin mold to ensure a wide viewing angle (typically 120° - 140°). * **Terminal Material:** Often uses gold or silver plating to ensure high solderability and resistance to corrosion. --- ### 3. Color Variations & Part Numbers The "SML-R12" prefix is followed by letters indicating the color and material composition: | Part Suffix | Color | Material | Wavelength ($\lambda_D$) | | :--- | :--- | :--- | :--- | | **V** | Red | AlGaInP | 630 nm | | **U** | Orange | AlGaInP | 605 nm | | **Y** | Yellow | AlGaInP | 590 nm | | **M** | Yellowish-Green | AlGaInP | 572 nm | | **P** | Green | GaP | 560 nm | --- ### 4. Schematic Representation In an electronic circuit, the SML-R1 is represented as a standard diode. Below is a simple implementation logic: ```c // Example: Driving an SML-R1 LED via a Microcontroller // VCC (3.3V) ---> Resistor (R) ---> SML-R1 (Anode) // SML-R1 (Cathode) ---> GND Calculation for Resistor: R = (V_source - V_forward) / I_forward R = (3.3V - 2.0V) / 0.02A = 65 Ohms ``` --- ### 5. Common Applications * **Automotive:** Dashboard illumination, switch lighting, and indicator panels. * **Consumer Goods:** Status indicators for smartphones, laptops, and wearables. * **Industrial:** Control panel signaling and diagnostic LEDs.