The **AA4040ZGS** is a high-performance, surface-mount (SMD) Light Emitting Diode (LED) manufactured by Kingbright. It belongs to the "Subminiature" series and is characterized by its specific right-angle lens design and high-intensity output. --- ### 1. Key Technical Specifications The "ZGS" suffix indicates the color and material composition (InGaN Green). Below are the primary electrical and optical characteristics: | Parameter | Specification | | :--- | :--- | | **Emitted Color** | Green | | **Material** | InGaN (Indium Gallium Nitride) | | **Lens Type** | Water Clear | | **Luminous Intensity** | ~500 mcd to 1000 mcd @ 20mA | | **Forward Voltage ($V_f$)** | 3.3V (Typical) / 4.1V (Max) | | **Forward Current ($I_f$)** | 30 mA (Max) | | **Dominant Wavelength** | 525 nm | | **Viewing Angle** | 120° | --- ### 2. Physical Dimensions and Package The AA4040 series uses a unique circular-shaped SMD package that is designed for side-emitting or right-angle mounting. * **Size:** 4.0mm x 4.0mm. * **Mounting:** Surface Mount Device (SMD). * **Orientation:** Right-angle surface mount, meaning the light is emitted parallel to the PCB surface. * **ESD Sensitivity:** InGaN devices are sensitive to static electricity; the AA4040ZGS typically includes an internal HBM (Human Body Model) rating of up to 450V. --- ### 3. Electronic Features & Usage The internal structure of this part includes specific features for industrial and commercial reliability: * **Low Power Consumption:** Optimized for high efficiency, providing bright green light with minimal current draw. * **Moisture Sensitivity Level (MSL):** Usually rated at Level 3, requiring proper storage to prevent damage during reflow soldering. * **Color Purity:** The InGaN material provides a true green (525nm) rather than the yellowish-green seen in older GaP technology. ### 4. Typical Applications * **Backlighting:** Used for LCDs, switches, and symbols. * **Status Indicators:** Power-on lights for consumer electronics. * **Edge Lighting:** Due to the right-angle design, it is ideal for lighting up light pipes or the edges of acrylic panels. --- ### 5. Simple Circuit Example To use this LED with a 5V microcontroller, a current-limiting resistor is required. ```python # Formula: R = (V_source - V_forward) / I_forward # Example: (5V - 3.3V) / 0.020A = 85 Ohms # Recommended Standard Resistor: 100 Ohms ```