### SML-R13BW: Technical Overview The **SML-R13BW** is a high-brightness, surface-mount (SMD) Light Emitting Diode (LED) manufactured by **ROHM Semiconductor**. It belongs to the SML-R1 series and is specifically designed for compact electronic applications requiring high reliability and efficient light output. --- ### 1. Key Technical Specifications | Parameter | Specification | |:---|:---| | **Color** | Blue | | **Material** | InGaN (Indium Gallium Nitride) | | **Package Size** | 1608 Metric (0603 Imperial) | | **Dimensions** | 1.6 x 0.8 x 0.36 mm | | **Dominant Wavelength** | 470 nm | | **Luminous Intensity** | 45 mcd (Typical at 20mA) | | **Forward Voltage (Vf)** | 3.2 V (Typical) | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Physical & Material Composition The SML-R13BW utilizes specific engineering to achieve its performance in a small footprint: * **Mini-mold Structure:** The "R1" series features a ultra-thin mold structure (0.36mm height), making it ideal for low-profile devices like smartphones or wearable tech. * **Reflector Design:** The internal structure is optimized for light collection, ensuring that despite its small size, the brightness remains visible even in daylight. * **Electrode Finish:** The terminals are typically gold-plated or tin-plated (depending on the specific sub-series) to ensure high solderability and resistance to oxidation. --- ### 3. Electrical Characteristics To integrate this part into a circuit, the following electrical behaviors must be considered: * **Forward Current (If):** The standard operating current is **20mA**. Exceeding the maximum rating (typically 30mA) will significantly shorten the lifespan or cause immediate failure. * **Polarity:** As a diode, it only conducts electricity in one direction. The package usually features a notch or a green mark on the cathode (-) side for orientation. * **Power Dissipation:** It is rated for approximately **66mW**. Designers must ensure proper heat dissipation through the PCB copper pads. --- ### 4. Common Applications Due to its "0603" form factor and high-intensity blue output, it is commonly found in: * **Status Indicators:** Power lights on consumer electronics. * **Backlighting:** Illumination for LCD screens or membrane switches. * **Automotive Interior:** Dashboard lighting and button illumination. * **Wearables:** Compact fitness trackers where space is at a premium. --- ### 5. Implementation Example (Basic Circuit) To use the SML-R13BW with a 5V power supply, a current-limiting resistor is required to prevent burnout: ```python # Calculation for Resistor (R): # R = (Source Voltage - Forward Voltage) / Desired Current # R = (5V - 3.2V) / 0.020A # R = 90 Ohms (Use 100 Ohm for safety) ```