## Overview of the HLMP-AD01-R0T00 The **HLMP-AD01-R0T00** is a high-brightness, precision optical performance **Oval LED** manufactured by Broadcom (formerly Avago/Agilent). It is specifically engineered for outdoor applications where visibility and durability are critical. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Color** | Amber (Red-Orange range) | | **Dominant Wavelength** | 590 nm | | **Luminous Intensity** | 460 mcd (Min) to 1900 mcd (Max) | | **Viewing Angle** | 70° x 35° (Oval) | | **Forward Voltage ($V_f$)** | 2.0V to 2.4V (Typical) | | **Forward Current ($I_f$)** | 20 mA (Standard operating current) | | **Lens Shape** | Oval 5mm (T-1 3/4) | | **Packaging** | Bulk | --- ### 2. Core Electronic Characteristics #### A. Optical Performance * **Precision Optical Design:** The "Oval" shape is not just aesthetic; it is designed to provide a wide horizontal viewing angle (70°) and a narrow vertical viewing angle (35°). This ensures that light is directed towards the audience/drivers rather than wasted towards the sky or the ground. * **AllnGaP Technology:** This LED utilizes Aluminum Indium Gallium Phosphide (AllnGaP) material, which provides high light output efficiency and stable performance over a wide temperature range. #### B. Electrical Requirements * **Current Regulation:** To ensure the longevity of the HLMP-AD01, a series resistor is required to limit the current to approximately **20mA**. * **Reverse Voltage:** The device has a maximum reverse voltage rating (typically 5V). Exceeding this can cause permanent breakdown of the PN junction. #### C. Environmental Durability * **Epoxy Material:** The LED is encapsulated in an advanced optical grade epoxy that contains **UV-A and UV-B inhibitors**. This prevents the lens from yellowing or becoming brittle when exposed to direct sunlight for long periods. --- ### 3. Common Applications Due to its specific viewing angle and high brightness, this part is commonly found in: * **Variable Message Signs (VMS):** Highway traffic boards. * **Solar Powered Signs:** Due to high efficiency (lumen per watt). * **Commercial Outdoor Advertising:** Large LED billboards. * **Passenger Information Signs:** Bus and train station displays. --- ### 4. Typical Circuit Integration To use this LED with a 5V microcontroller (like an Arduino), the calculation for the current limiting resistor ($R$) is as follows: ```python # Ohms Law: R = (V_source - V_forward) / I_forward v_source = 5.0 # Volts v_forward = 2.1 # Typical Volts for Amber i_forward = 0.02 # 20mA in Amps resistor_value = (v_source - v_forward) / i_forward print(f"Required Resistor: {resistor_value} Ohms") # Result: 145 Ohms (Use a standard 150 Ohm resistor) ```