### C503B-RAS Electronic Specifications The **C503B-RAS** is a high-brightness, through-hole Light Emitting Diode (LED) manufactured by **Cree LED**. It belongs to the 5mm round LED family, specifically designed for outdoor signage and indicator applications. --- ### 1. Key Technical Specifications The following table summarizes the primary electrical and optical characteristics: | Parameter | Specification | | :--- | :--- | | **Color** | Red | | **Wavelength (Typical)** | 624 nm (Dominant) / 628 nm (Peak) | | **Luminous Intensity** | 5860 - 12000 mcd (millicandela) | | **Viewing Angle** | 15 Degrees | | **Forward Current ($I_F$)** | 50 mA (Maximum) | | **Forward Voltage ($V_F$)** | 2.1V (Typical) / 2.6V (Maximum) | | **Reverse Voltage ($V_R$)** | 5V | | **Lens Appearance** | Red / Tinted / Diffused (Depending on sub-variant) | --- ### 2. Physical Dimensions and Build * **Package Type:** 5mm (T-1 3/4) through-hole. * **Material:** AlGaInP (Aluminium Gallium Indium Phosphide) on GaAs substrate. This material choice allows for high efficiency and high light output. * **Lead Frame:** Standard two-wire lead (Anode and Cathode). * **Standoffs:** This model usually comes with **standoffs** (small protrusions on the leads) to ensure consistent spacing from the PCB during soldering. --- ### 3. Absolute Maximum Ratings To avoid damaging the component, the following limits must be observed (at $T_A = 25^\circ C$): * **Continuous Forward Current:** 50 mA. * **Peak Forward Current:** 200 mA (Duty cycle 1/10, 1kHz). * **Power Dissipation:** 130 mW. * **Operating Temperature:** $-40^\circ C$ to $+100^\circ C$. * **Storage Temperature:** $-40^\circ C$ to $+100^\circ C$. --- ### 4. Implementation Circuit When connecting the C503B-RAS to a standard 5V power supply (like an Arduino or logic board), a current-limiting resistor is required. **Example Calculation:** To run the LED at a safe **20mA** using a **5V** supply: $$R = \frac{V_{source} - V_F}{I_F} = \frac{5V - 2.1V}{0.02A} = 145 \Omega$$ *(Common resistor value: $150 \Omega$)* ```cpp // Example: Basic Blink Logic for C503B-RAS void setup() { pinMode(LED_BUILTIN, OUTPUT); } void loop() { digitalWrite(LED_BUILTIN, HIGH); // LED ON delay(1000); digitalWrite(LED_BUILTIN, LOW); // LED OFF delay(1000); } ``` ---