The **LSR9033/T/TR2-R** is a specific surface-mount (SMD) Light Emitting Diode (LED) manufactured by **Everlight Electronics**. It belongs to the subminiature chip LED category, often used for status indication or backlighting in compact electronic devices. --- ### 1. General Specifications The following table outlines the primary electrical and optical characteristics typical for this series (Red color variant): | Parameter | Specification (Typical) | | :--- | :--- | | **Type** | Subminiature Chip LED | | **Color** | Brilliant Red | | **Wavelength** | 624 nm - 632 nm (Dominant) | | **Forward Current ($I_F$)** | 20 mA (Continuous) | | **Forward Voltage ($V_F$)** | 2.0V (Typical) / 2.4V (Max) | | **Luminous Intensity ($I_V$)** | ~15 - 40 mcd | | **Viewing Angle** | 120° | | **Mounting Type** | SMD (Surface Mount Device) | --- ### 2. Physical Construction and Package The "LSR" designation identifies the material and color (Liquid Phase Epitaxy AlGaInP Red), while the suffix "TR2" denotes the packaging style. * **Subminiature Design:** These LEDs are significantly smaller than standard 1206 or 0805 SMD LEDs, designed for high-density PCB layouts. * **Encapsulation:** Clear epoxy resin is used to allow for maximum light output and a wide viewing angle. * **Tape and Reel (TR):** The "TR2" indicates that the component is supplied on an 8mm embossed carrier tape on a 7-inch diameter reel, which is industry-standard for automated SMT (Surface Mount Technology) assembly. --- ### 3. Key Electronic Characteristics To integrate this part into a circuit, two main factors must be considered: #### A. Thermal Management Since this is a subminiature component, it has a small surface area for heat dissipation. Operating it at its maximum rated current (typically 25mA-30mA absolute max) without a proper current-limiting resistor will lead to rapid thermal degradation. #### B. Driving the LED The LED should be driven via a constant current source or a simple series resistor. The resistor value ($R$) can be calculated using Ohm's Law: `R = (V_source - V_F) / I_F` ```python # Example Calculation for a 5V Circuit V_source = 5.0 # Volts V_f = 2.0 # Typical Forward Voltage for LSR9033 I_f = 0.02 # Desired Current (20mA) resistor_value = (V_source - V_f) / I_f print(f"Required Resistor: {resistor_value} Ohms") # Result: 150 Ohms ``` --- ### 4. Common Applications * **Backlighting:** Used for membrane switches and LCD displays. * **Status Indicators:** Small "On/Off" or "Error" lights in consumer electronics (smartphones, wearables). * **Telecommunications:** Signal indicators on modems and routers.