15-21UYD/S530-A3/TR8

The 15-21UYD/S530-A3/TR8 from Everlight Electronics is a high-brightness surface-mount yellow LED designed for general-purpose indication and backlighting applications. Featuring an AlGaInP (Aluminum Gallium Indium Phosphide) chip that emits yellow light with a dominant wavelength of 589nm, this 1206-size (3.20mm × 1.50mm) chip LED delivers typical luminous intensity of 57mcd at 20mA forward current through a water-clear lens with a wide 130° viewing angle. The wide viewing angle ensures uniform light distribution, making it ideal for backlighting LCD panels, switches, and symbol indicators. The device is rated for 25mA continuous forward current with a typical forward voltage of 2.0V, and can handle peak currents up to 160mA under pulsed conditions (10% duty cycle at 1kHz). Packaged in 8mm tape on 7″ diameter reels with 2,000 pieces per reel, these LEDs are fully compatible with high-speed automated SMT assembly processes and support both infrared and vapor-phase reflow soldering. With an operating temperature range of -40°C to +85°C and 2,000V ESD protection (HBM), the 15-21UYD series provides reliable performance in automotive, telecommunications, consumer electronics, and industrial applications.

The 15-21UYD/S530-A3/TR8 operates on the principle of electroluminescence in a semiconductor p-n junction. The LED chip is fabricated from AlGaInP (Aluminum Gallium Indium Phosphide), a III-V compound semiconductor whose bandgap energy corresponds to yellow light wavelengths in the 580-595nm range. When a forward bias voltage is applied across the p-n junction, electrons from the n-region and holes from the p-region are injected across the depletion region and recombine in the active layer. This recombination process releases energy in the form of photons (light). The wavelength of the emitted light is determined by the bandgap energy of the semiconductor material. The AlGaInP material system enables high internal quantum efficiency and bright emission in the yellow-to-red spectral range. The light exits through the top of the chip through the transparent semiconductor material and the clear epoxy lens. The 130° viewing angle is achieved through the combination of chip geometry, reflector design, and lens shape, which spreads the light widely for uniform illumination. A current-limiting resistor must be used in series with the LED to control the forward current and prevent damage, as even small increases in forward voltage can cause large increases in forward current due to the diode I-V characteristic.

Polarity Identification: The cathode side is typically marked with a notch or bevel on the package edge. For surface-mount LEDs, the cathode pad may have a different shape or be marked with a line on the component body. Always verify polarity from the datasheet before assembly. Overcurrent or reverse-polarity operation can damage the LED.

• Automotive Dashboard: Used for instrument cluster indicators, warning lights, and switch backlighting in automotive interiors
• Telecommunications: Serves as status indicators in telephones, fax machines, modems, and network equipment including routers and switches
• LCD Backlighting: Provides flat backlight illumination for small LCD panels, switches, and symbolic indicators in consumer and industrial devices
• Consumer Electronics: Deployed in TVs, audio equipment, set-top boxes, and home appliances as power and function indicators
• Industrial Control: Used in PLC panels, control cabinets, and test equipment for status and fault indication
• Power Supplies & Chargers: Serves as power-on, charging, and fault indicators in AC/DC adapters, battery chargers, and power supply units
• Computer Peripherals: Provides status indication in servers, storage devices, and networking equipment
• General Indication: Suitable for any application requiring a compact, surface-mount yellow indicator light with good visibility