The **KA-4008ZGS** is a high-performance Surface Mount Device (SMD) Light Emitting Diode (LED) manufactured by Kingbright. It belongs to the "Sidelooking" category, designed for applications where light needs to be emitted parallel to the PCB. --- ### 1. Technical Specifications The following table summarizes the primary electrical and optical characteristics of the KA-4008ZGS (based on typical InGaN Green technology): | Parameter | Specification | | :--- | :--- | | **Material** | InGaN (Indium Gallium Nitride) | | **Emitting Color** | Green | | **Lens Type** | Water Clear | | **Luminous Intensity** | ~300 - 600 mcd @ 20mA | | **Forward Voltage (Vf)** | 3.3V (Typ) / 4.1V (Max) | | **Wavelength** | 525 nm (Dominant) | | **Viewing Angle** | 120° | | **Package Size** | 4.0mm x 0.8mm (Side Looker) | --- ### 2. Key Electronic Features * **Sidelooking Design:** Unlike standard LEDs that shine "up" from the board, this part is engineered to emit light from the side. This is crucial for edge-lighting LCD displays or status indicators on the side of a device casing. * **InGaN Technology:** This material allows for high brightness and efficiency in the green spectrum compared to older GaP technologies. * **Low Power Consumption:** Operates efficiently at standard 20mA current, making it suitable for battery-powered portable electronics. * **ESD Sensitivity:** Being an InGaN-based device, it is sensitive to Static Electricity (ESD). Use of an ionizer or grounded wrist straps is required during assembly. --- ### 3. Pin Configuration and Dimensions The "4008" designation refers to its physical footprint: * **Length:** 4.0 mm * **Width:** 0.8 mm * **Orientation:** The cathode is typically identified by a notch or a polarity mark on the underside of the SMD package. ### 4. Common Applications 1. **Backlighting:** Used for small LCD screens and membrane switches. 2. **Edge Lighting:** Illuminating light pipes or acrylic panels. 3. **Status Indicators:** Low-profile indicators for thin consumer electronics (smartphones, tablets). 4. **Coupling:** Optical coupling in tight mechanical spaces. --- ### 5. Recommended Operating Circuit To prevent damage, a current-limiting resistor must be used in series. ```python # Formula to calculate the Resistor (R): # R = (V_source - V_forward) / I_forward # Example for a 5V Source: # V_source = 5.0V # V_forward = 3.3V # I_forward = 0.02A (20mA) Resistance = (5.0 - 3.3) / 0.02 # Result: 85 Ohms (Use the next standard value, e.g., 100 Ohms) ```