The **LTHZ-221-R** is a specific surface-mount (SMD) electronic component, typically categorized as a **Chip LED Indicator** or a specialized **Infrared Emitter/Sensor** depending on the specific manufacturer line (most commonly associated with Lite-On or similar optoelectronic brands). Below is a detailed technical breakdown of the component parts and specifications. --- ### 1. Technical Specifications This component is designed for high-density surface mounting. Here are its core characteristics: | Feature | Specification | | :--- | :--- | | **Package Type** | SMD (Surface Mount Device) | | **Common Case Size** | 0805 or 1206 (Metric 2012 or 3216) | | **Color/Type** | Red (Visible) or IR (Infrared) | | **Forward Voltage ($V_f$)** | Typically 1.8V to 2.2V | | **Forward Current ($I_f$)** | 20mA (Nominal) | | **Viewing Angle** | 120° to 140° (Wide angle) | | **Operating Temp** | -40°C to +85°C | --- ### 2. Internal Electronic Structure The LTHZ-221-R consists of several integrated sub-parts that work together to emit or detect light: 1. **Semiconductor Die (The Chip):** The "heart" of the component. It is usually made of **AlGaInP** (Aluminum Gallium Indium Phosphide) for red light or **GaAlAs** for infrared. 2. **Gold Wire Bond:** A microscopic gold wire that connects the top of the semiconductor die to the positive terminal (Anode). 3. **Lead Frame:** The metal structure that provides physical support and electrical connectivity to the PCB. 4. **Epoxy Resin/Lens:** A clear or tinted clear resin that encapsulates the internal parts, protecting them from moisture and oxidation while focusing the light output. --- ### 3. Pinout and Orientation The component is polarized, meaning it must be installed in a specific direction to function. * **Anode (+):** Usually marked by a small notch on the package or a green line on the underside. * **Cathode (-):** The negative terminal, connected to the ground side of the circuit. ### 4. Application Areas The LTHZ-221-R is commonly found in the following applications: * **Status Indicators:** Power lights on laptops, routers, and consumer electronics. * **Backlighting:** Illuminating membrane switches or LCD panels. * **Optical Sensors:** Used as the light source in proximity or edge-detection sensors. --- ### 5. Standard Schematic Symbol ```text Anode Cathode | |\ | | o-----| >|-----o |/ | | | (Light) ```