## SML-R12DWT87P: Electronic Component Overview The **SML-R12DWT87P** is a high-brightness surface-mount (SMD) Light Emitting Diode (LED) manufactured by **ROHM Semiconductor**. It belongs to the SML-R12 series, characterized by its compact size and high reliability. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Color** | Orange (High Brightness) | | **Wavelength ($\lambda_D$)** | 605 nm | | **Package Size** | 1608 Metric (0603 Imperial) | | **Dimensions** | 1.6 x 0.8 mm (Height: 0.36 mm) | | **Luminous Intensity** | 100 - 160 mcd (typical) | | **Forward Voltage ($V_F$)** | 2.2 V (typical) | | **Forward Current ($I_F$)** | 20 mA | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Physical Construction and Features * **Mini-Mold Structure:** The "R12" designation refers to the specific ultra-compact mold technology used by ROHM, which allows for a very low profile (thinness). * **Material:** It typically utilizes **AlGaInP** (Aluminum Gallium Indium Phosphide) on a GaAs substrate, which is the standard for high-efficiency orange and red LEDs. * **Taping Specification:** The "T87P" suffix refers to the packaging method (tape and reel), specifically designed for automated pick-and-place assembly machines. --- ### 3. Pinout and Orientation The SML-R12DWT87P is a polarized component with two terminals: 1. **Anode (+):** The positive terminal. 2. **Cathode (-):** The negative terminal, usually marked on the bottom of the package or by a notch in the mold to ensure correct orientation during soldering. --- ### 4. Application Areas Due to its small footprint and brightness, this LED is commonly used in: * **Consumer Electronics:** Indicator lights for smartphones, tablets, and wearables. * **Automotive:** Dashboard illumination and button backlighting. * **Industrial:** Status indicators on high-density PCB boards. --- ### 5. Implementation Example (Current Limiting) To prevent damaging the LED, a resistor must be placed in series. Using Ohm's Law ($R = (V_{source} - V_F) / I_F$): ```python # Calculation for a 5V source source_voltage = 5.0 forward_voltage = 2.2 target_current = 0.020 # 20mA resistor_value = (source_voltage - forward_voltage) / target_current print(f"Required Resistor: {resistor_value} Ohms") # Result: 140 Ohms ```