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XL-257UYC-L SMD LED — Technical Specifications & Design Guide

The XL-257UYC-L from XINGLIGHT is a LED designed for indicator and backlight applications.

XL-257UYC-L SMD LED — Technical Specifications & Design Guide

📌 Product Overview

The XL-257UYC-L is a standard 3mm radial LED from XINGLIGHT, utilizing a yellow chip encapsulated in a white water-clear colloid to enhance light contrast. It is designed primarily for through-hole assembly (THT) processes where robust physical mounting and wide-angle visibility are required. With a dominant wavelength of 585–595nm, this component serves as a reliable indicator light in general-purpose circuitry. 💡 The design focus here is on balancing luminous intensity with energy efficiency, offering a typical forward voltage of 2.2V to minimize power consumption in battery-operated or densely populated boards.

🛠️ Typical Applications

  • Status & Signal Indication: Ideal for power on/off indicators and status displays in home appliances and digital communication devices.
  • Automotive Electronics: Suitable for non-critical interior instrument panel lighting, provided the specific automotive temperature grades are verified against the datasheet.
  • Consumer Electronics: Integration into electronic toys, electronic clocks, and educational equipment where cost-effective visual feedback is required.
  • Industrial & Decorative: Usage in urban lighting projects and traffic instruction signs, leveraging the 110-degree viewing angle for high visibility.

📊 Key Technical Specifications

The following optical and electrical parameters are measured under standard test conditions (Ta=25°C, IF=20mA). ⚡ Engineers should pay close attention to the Luminous Intensity (Iv) and Forward Voltage (VF) binning codes to ensure consistency in mass production.

ParameterSymbolMinTypMaxUnitTest Condition
Luminous IntensityIv50200300mcdIF = 20mA
Dominant Wavelengthλd585-595nmIF = 20mA
Peak Wavelengthλp-590-nmIF = 20mA
Forward VoltageVF1.82.22.4VIF = 20mA
Viewing Angle2Ø1/2-110-degIF = 20mA
Reverse CurrentIR--≤10μAVR = 5V

⚠️ Absolute Maximum Ratings & Process Limits

Exceeding these ratings may cause permanent device failure or degradation of optical performance. 🔒 Design margins must account for the Power Dissipation (Pd) limit and thermal environments.

ParameterSymbolRatingUnitNotes
Power DissipationPd70mWDerate above 25°C ambient
Max Continuous Forward CurrentIF20mADC operation
Peak Forward CurrentIFp80mAPulse width/duty cycle limited
Operating TemperatureTopr-20 ~ +85°CAmbient range
Storage TemperatureTstg-40 ~ +85°CNon-operating
Soldering (Wave)Tsol240°C≤6 seconds duration
Soldering (Manual)Tsol300°C≤3 seconds duration

⚠️ Critical Note: The soldering point must be kept at least 2.0mm away from the colloid base to prevent thermal damage to the epoxy.

📦 Package, Dimensions & Assembly Notes

The XL-257UYC-L features a 5mm (T-1 3/4) radial package with long leads, conforming to EIA standard packaging dimensions.

  • Dimensions: The outer diameter is approximately 5.0mm, with a total length of 28mm including the leads.
  • Tolerance: Unless specified, dimensional tolerances are ±0.50mm.
  • Assembly: The component is packed in moisture-proof and anti-static foil bags. It has a Moisture Sensitivity Level (MSL) of 2.
  • Soldering: Recommended for standard wave soldering or manual soldering processes. Ensure the 2.0mm clearance from the base is maintained during the soldering operation to avoid compromising the internal bond wires.

🚀 Sourcing & Supply Considerations

When integrating the XL-257UYC-L into your BOM, consider the following supply chain factors to ensure yield and consistency:

  • Binning Verification: Always specify the Brightness (A1-A3) and Voltage (N12-7/8/9) bin codes to your distributor to avoid brightness variation in the final product.
  • Authenticity: Verify packaging markings to ensure compliance with ROHS environmental standards.
  • Sample Testing: Given the ±10% light intensity tolerance, request a sample batch to validate the actual brightness against your specific diffuser or lens design.
  • Lead Time: As a standard radial LED, lead times are generally stable, but confirm stock availability for high-volume orders to prevent production line stoppages.

❓ FAQ

Q: What is the correct soldering profile for this LED to prevent damage?
A: For wave soldering, do not exceed 240°C for 6 seconds. For manual welding, the limit is 300°C for 3 seconds. Crucially, the soldering point must be >2.0mm from the bottom of the epoxy body to prevent thermal stress damage.

Q: Can the XL-257UYC-L be used in automotive outdoor applications?
A: While it is listed under "Automotive Electronics," the operating temperature range is -20°C to +85°C. For under-hood or extreme exterior environments, you may need a component with a wider temperature range (e.g., -40°C to +100°C).

Q: How do I interpret the brightness grading codes?
A: The datasheet specifies three bins: A1 (50-100 mcd), A2 (100-200 mcd), and A3 (200-300 mcd). Selecting a specific bin code ensures that all LEDs in your batch have uniform brightness.

Q: What does "White Water Colloid" mean for the light output?
A: It refers to the clear epoxy casing. When the LED is off, it looks clear/white. When on, it emits the yellow light of the chip. This typically provides a higher luminous intensity and a wider viewing angle compared to diffused colored lenses.

Q: Is this component RoHS compliant?
A: Yes, the datasheet explicitly states that the XL-257UYC-L is an environmental protection product meeting ROHS requirements, making it suitable for EU and other international markets with hazardous substance restrictions.

About Leon Zhang

Leon Zhang is the founder of LDeepAI, focusing on AI-assisted electronic component sourcing and verified China supply-chain support for overseas buyers. He previously worked within the Huaqiang Group ecosystem, including experience related to HQEW, one of China's well-known electronic component trading platforms. This background gives him practical insight into China's electronic component supply-chain structure, supplier screening, channel verification and cross-border sourcing workflows.

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