The **VLMD31.._V02** series refers to high-intensity Surface Mount Device (SMD) LEDs manufactured by Vishay Semiconductors. These are specifically designed using AllnGaP (Aluminum Indium Gallium Phosphide) technology, which provides high luminous intensity in a compact PLCC-2 package. --- ### 1. Key Technical Specifications The following table highlights the core electrical and optical characteristics of the VLMD31 series (typical values at $T_{amb} = 25^\circ C$): | Parameter | Symbol | Typical Value | Unit | | :--- | :--- | :--- | :--- | | **Forward Current** | $I_F$ | 20 | mA | | **Forward Voltage** | $V_F$ | 2.0 (Max 2.6) | V | | **Luminous Intensity** | $I_V$ | 71 to 180 | mcd | | **Dominant Wavelength** | $\lambda_d$ | 605 (Orange/Amber) | nm | | **Viewing Angle** | $\phi$ | ± 60° (120° total) | deg | | **Power Dissipation** | $P_V$ | 130 | mW | --- ### 2. Physical Design and Packaging The parts utilize the industry-standard **PLCC-2 package**, which is highly reliable for automated assembly processes. * **Package Dimensions:** $3.0 \times 2.8 \times 1.75$ mm. * **Lead Frame:** Lead-free (Pb-free) and RoHS compliant. * **Encapsulation:** Clear epoxy resin, providing a wide viewing angle without internal diffusion. * **Mounting:** Compatible with IR reflow, vapor phase, and wave soldering processes. --- ### 3. Application Use Cases Due to their high reliability and AEC-Q101 qualification (automotive grade), these LEDs are commonly found in: 1. **Automotive Interior:** Dashboard lighting, switches, and radio displays. 2. **Industrial Indicators:** Status lights for control panels and power supplies. 3. **Backlighting:** LCD displays, symbols, and illuminated push-buttons. 4. **Telecommunications:** Indicator lights for routers and server hardware. --- ### 4. Circuit Example To drive a VLMD31 LED using a 5V DC source, a current-limiting resistor is required. ```cpp // Calculation for a 20mA current: // R = (V_source - V_forward) / I_forward // R = (5V - 2.0V) / 0.020A = 150 Ohms ``` ---