📌 Product Overview
The XL-257SURC-L is a standard 3mm through-hole LED designed for reliable indication and illumination in general electronic circuits. It features a red diffused chip encapsulated in a white water-clear colloid, providing a dominant wavelength of 620nm.
💡 This component is engineered for low-voltage DC drive systems, offering a balance between luminous intensity and power consumption. It is suitable for applications requiring long operating life and fast startup times under standard environmental conditions.
🎯 Typical Applications
Based on its 3mm form factor and optical characteristics, the XL-257SURC-L is utilized across various sectors:
- Consumer Electronics: Status indicators for home appliances and digital devices.
- Automotive: Interior dashboard lighting and auxiliary indicators (non-critical).
- Industrial & Communication: Signal feedback for communication equipment and control panels.
- Education & Toys: Electronic teaching aids and electronic toy indicators.
- Decorative Lighting: Urban lighting projects and small-scale decorative fixtures.
⚡ Key Technical Specifications
The following table outlines the initial electrical and optical characteristics at $T_a=25^\circ C$:
| Parameter | Symbol | Min. | Typ. | Max. | Unit | Test Conditions |
|---|---|---|---|---|---|---|
| Luminous Intensity | $I_V$ | 50 | 200 | 300 | mcd | $I_F = 20\text{mA}$ |
| Dominant Wavelength | $\lambda_d$ | 615 | 620 | 625 | nm | $I_F = 20\text{mA}$ |
| Forward Voltage | $V_F$ | 1.8 | 2.2 | 2.4 | V | $I_F = 20\text{mA}$ |
| Viewing Angle | $2\theta_{1/2}$ | - | 110 | - | deg | $I_F = 20\text{mA}$ |
| Reverse Current | $I_R$ | - | - | $\le 10$ | $\mu\text{A}$ | $V_R = 5\text{V}$ |
💡 Design Note: Luminous intensity varies by bin code (A1: 50-100mcd, A2: 100-200mcd, A3: 200-300mcd). Voltage grading is also available (N12-7 to N12-9).
🚨 Absolute Maximum Ratings & Process Limits
Exceeding these ratings may cause device failure or degradation. Design margins must account for these limits under varying operating temperatures.
| Parameter | Symbol | Rating | Unit | Notes |
|---|---|---|---|---|
| Power Dissipation | $P_D$ | 70 | mW | |
| Max Forward Current | $I_F$ | 20 | mA | Continuous DC |
| Peak Forward Current | $I_{Fp}$ | 80 | mA | Pulse width/duty cycle limits apply |
| Operating Temp. | $T_{opr}$ | -20 to +85 | $^\circ\text{C}$ | |
| Storage Temp. | $T_{stg}$ | -40 to +85 | $^\circ\text{C}$ | |
| Soldering (Wave) | $T_{sol}$ | 240 | $^\circ\text{C}$ | $\le 6\text{s}$, $>2.0\text{mm}$ from body |
🔒 Critical Warning: Ensure solder joints are maintained at a distance of at least 2.0mm from the colloid bottom to prevent thermal damage to the epoxy.
📦 Package, Dimensions & Assembly Notes
- Package Type: 3mm Radial Lead (Long leg).
- Dimensions: $5.0 \times 2.0 \times 7.0 \times 28\text{mm}$ (L x W x H x Total Length).
- Tolerance: $\pm 0.50\text{mm}$ unless otherwise specified.
- Moisture Sensitivity: MSL Level 2.
- Assembly: Designed for wave soldering or manual welding. Do not exceed manual welding limits of $300^\circ\text{C}$ for 3 seconds.
📈 Sourcing & Supply Considerations
- Packaging: EIA standard compliant, shipped in moisture-proof and anti-static foil bags.
- Compliance: Fully RoHS compliant (Environmental protection).
- Quality Control: Binning codes for Brightness, Voltage, and Wavelength allow for specific selection consistency.
- Authenticity: Verify packaging integrity and MSL labels upon receipt to ensure storage condition compliance.
❓ FAQ
Q: What is the forward voltage requirement for this LED?
A: The typical forward voltage ($V_F$) is 2.2V, with a maximum of 2.4V at 20mA. Ensure your driving circuit can supply sufficient voltage while limiting current to 20mA.
Q: Can this LED be used in high-humidity environments?
A: Yes, it has passed high-temperature and high-humidity endurance tests ($85^\circ\text{C}$, 85-90% RH). However, for long-term storage or use in harsh conditions, verify the sealing of the final housing.
Q: What are the soldering limits for PCB assembly?
A: For wave soldering, do not exceed $240^\circ\text{C}$ for more than 6 seconds. For manual welding, the limit is $300^\circ\text{C}$ for 3 seconds. Keep the heat source $>2.0\text{mm}$ away from the LED body.
Q: How is brightness consistency controlled?
A: The manufacturer uses brightness grading codes (A1, A2, A3). To ensure visual uniformity in mass production, specify a single bin code (e.g., A2) when placing orders.
Q: What is the expected lifespan?
A: Datasheet reliability testing indicates a working life of at least 1000 hours under standard conditions ($25^\circ\text{C}$, 20mA), though actual operational life typically extends much further under nominal usage.
