Yellow LED Chip 1.8x0.8x0.5mm - Forward Voltage 1.8-2.4V - Power 78mW - SMD Datasheet

1. Product Overview

The RF-YG1808TS-AC-E0 is a compact yellow chip LED designed for general-purpose indication and illumination. Housed in a miniature 1.8mm x 0.8mm x 0.50mm SMD package, it offers an extremely wide viewing angle of 140 degrees, making it suitable for applications requiring uniform light distribution. The device is fabricated using a high-efficiency yellow chip with typical dominant wavelength in the range of 585nm to 595nm. It supports standard SMT assembly processes and is RoHS compliant. With a moisture sensitivity level of 3, proper handling and storage conditions must be observed.

2. Technical Parameter Deep Dive

2.1 Electro-Optical Characteristics (at Ts=25°C, IF=20mA)

• Dominant Wavelength (λD): 585-595nm (binned into D10, D20, E10, E20 sub-ranges)
• Forward Voltage (VF): 1.8V to 2.4V (binned into B1, B2, C1, C2, D1, D2 sub-ranges)
• Luminous Intensity (IV): 350-800 mcd (binned into J10, J20, K10, K20 sub-ranges)
• Spectral Half Bandwidth (Δλ): Typically 15 nm
• Viewing Angle (2θ1/2): 140 degrees (typical)
• Reverse Current (IR): ≤10 μA at VR=5V
• Thermal Resistance (RTHJ-S): ≤260 K/W

2.2 Absolute Maximum Ratings

• Power Dissipation (Pd): 78 mW
• Forward Current (IF): 30 mA (continuous); 60 mA (pulse, 1/10 duty, 0.1ms width)
• ESD (HBM): 2000 V
• Operating Temperature (Topr): -40°C to +85°C
• Storage Temperature (Tstg): -40°C to +85°C
• Junction Temperature (Tj): 95°C (maximum)

3. Binning System Explanation

The product is sorted into fine bins for wavelength, luminous intensity, and forward voltage to ensure consistent performance in end applications.

• Wavelength Bins: D10 (585-587.5nm), D20 (587.5-590nm), E10 (590-592.5nm), E20 (592.5-595nm)
• Intensity Bins: J10 (350-430 mcd), J20 (430-530 mcd), K10 (530-650 mcd), K20 (650-800 mcd)
• Voltage Bins: B1 (1.8-1.9V), B2 (1.9-2.0V), C1 (2.0-2.1V), C2 (2.1-2.2V), D1 (2.2-2.3V), D2 (2.3-2.4V)

All measurements have specified tolerances: ±0.1V for forward voltage, ±2nm for dominant wavelength, and ±10% for luminous intensity.

4. Performance Curve Analysis

4.1 Forward Voltage vs. Forward Current (Fig. 1-6)

The forward voltage increases monotonically with current. At the test condition IF=20mA, VF typically falls in the 1.8-2.4V range. Applying the maximum rated current (30mA) will require a slightly higher drive voltage.

4.2 Relative Intensity vs. Forward Current (Fig. 1-7)

Relative light output increases non-linearly with current. The curve shows that at lower currents the slope is steeper, indicating higher efficiency at lower drive currents. At 20mA the relative intensity is approximately 1.0 (normalized).

4.3 Pin Temperature vs. Relative Intensity (Fig. 1-8)

As junction temperature rises, relative intensity declines. At 100°C, intensity drops to about 0.7 of the value at 25°C. Proper thermal management is essential to maintain brightness.

4.4 Pin Temperature vs. Forward Current Derating (Fig. 1-9)

Maximum allowable forward current must be reduced as pin temperature increases. At 100°C, the safe current is approximately 10mA, compared to 30mA at 25°C. This derating curve must be considered in high-temperature environments.

4.5 Forward Current vs. Dominant Wavelength (Fig. 1-10)

The dominant wavelength shifts slightly with current. At 20mA the wavelength is approximately 591nm. As current increases from 0 to 30mA, the wavelength changes by less than 2nm, demonstrating good color stability.

4.6 Relative Intensity vs. Wavelength (Fig. 1-11)

The emission spectrum peaks near 590nm with a half-bandwidth of 15nm. The spectral distribution is narrow, providing a saturated yellow color.

4.7 Radiation Pattern (Fig. 1-12)

The angular radiation is Lambertian-type with a wide half-angle of 140°. The intensity remains relatively uniform from -70° to +70° off axis.

5. Mechanical and Packaging Information

5.1 Package Dimensions (Figs. 1-1 to 1-4)

• Dimensions: 1.80mm x 0.80mm x 0.50mm (tolerance ±0.2mm)
• Polarity: See Fig. 1-4 for pad identification (pad 1 and pad 2)
• Soldering Pattern (Fig. 1-5): Recommended copper land pattern dimensions 0.95mm x 0.80mm (pad spacing 1.3mm, total width 2.6mm). Note that the view from bottom shows pad geometry.

5.2 Carrier Tape and Reel (Figs. 2-1, 2-2)

• Carrier tape: 8mm width, pocket pitch 4.00mm, thickness 0.65mm. Features polarization mark and feeding direction.
• Reel: diameter 178mm, width 8.0mm, hub diameter 60mm, tape slot 13.0mm.
• Quantity: 4000 pcs per reel.

5.3 Label and Moisture Barrier Bag (Figs. 2-3, 2-4)

The label includes Part Number, Spec Number, Lot Number, Bin Code, Luminous Flux, Chromaticity Bin, Forward Voltage, Wavelength, Quantity, and Date. Products are packed in a Moisture Barrier Bag (MBB) with desiccant and a humidity indicator card to maintain moisture level below MSL-3 threshold.

6. Soldering and Assembly Guidelines

6.1 Recommended Reflow Profile (Fig. 3-1, Table 3-1)

• Preheat: Ramp-up ≤3°C/s; Tsmin=150°C, Tsmax=200°C; time 60-120s
• Ramp-up to TL (217°C): 60-150s
• Time above 217°C (tL): 60-120s
• Peak temperature (TP): 260°C, maximum time within 5°C of peak (tp): 10s
• Cooling: ≤6°C/s
• Total time from 25°C to peak: ≤8 minutes

Reflow soldering should not exceed 2 times. If more than 24 hours between solders, the LEDs may be damaged.

6.2 Soldering Iron and Repair

Manual soldering: temperature <300°C, time <3s, only one time. For repair, a double-head soldering iron is recommended; pre-test to confirm no damage.

6.3 Handling Precautions

• Avoid mechanical stress on LEDs during and after soldering.
• Do not warp the PCB after mounting.
• Do not cool rapidly after soldering.
• Do not apply excessive vibration during cool-down.

7. Application Recommendations

7.1 Typical Applications

• Optical indicators (status, warning lights)
• Switches, symbols, and display backlighting
• General-purpose illumination in small form factors

7.2 Design Considerations

• Use current-limiting resistors; small voltage changes can cause large current swings leading to thermal runaway.
• Ensure good thermal dissipation; keep junction temperature below 95°C.
• Avoid reverse voltage; design circuits to apply forward voltage only.
• In series/parallel arrays, consider current distribution and heat sharing.
• Environmental sulfur content should be below 100 ppm; halogen content (bromine, chlorine) individually below 900 ppm and total below 1500 ppm.
• Avoid VOCs that can outgas and attack silicone encapsulant; use tested adhesives.

8. Storage and Shelf Life

If moisture indicator card shows pink (desiccant faded) or storage time exceeded, bake at 60±5°C for 24 hours before use.

9. Reliability Test Summary

The product has passed the following tests (JEDEC standards) with acceptance criteria of 0/1 failure:

• Reflow (260°C, 10s, 2x) – 22 pcs
• Temperature cycle (-40°C to 100°C, 100 cycles)
• Thermal shock (-40°C to 100°C, 300 cycles)
• High temperature storage (100°C, 1000h)
• Low temperature storage (-40°C, 1000h)
• Life test (Ta=25°C, IF=20mA, 1000h)

Judgment criteria: VF change ≤1.1x USL, IR ≤2x USL, luminous flux ≥0.7x LSL.

10. Typical Performance Characteristics

• Forward Voltage vs. Current: Non-linear increase; operate at 20mA for optimal efficiency.
• Intensity vs. Current: Sub-linear; higher current yields diminishing returns in brightness.
• Temperature dependence: Intensity drops ~30% at 100°C; derate current accordingly.
• Wavelength stability: <2nm shift over operating current range.
• Radiation pattern: Wide 140° viewing angle, suitable for backlighting and indicator panels.

11. Design Case Study: Optical Indicator Module

Consider a user interface panel requiring a yellow status LED visible over ±70°. Using the 1808 package allows dense placement. With 20mA drive and a 100Ω series resistor (assuming VF≈2.0V on a 5V rail), power dissipation is 78mW, well within limits. For wide temperature range (-40°C to +85°C), ensure thermal design keeps junction below 95°C. Using the provided soldering pattern and reflow profile ensures reliable solder joints. If the application demands consistent color, select the appropriate wavelength bin (e.g., E20 for 592.5-595nm). The ultra-small footprint (1.8×0.8mm) enables compact PCB layouts with high component density.

12. Underlying Principle: How the Yellow LED Works

The LED is fabricated using a yellow chip—typically InGaAlP (indium gallium aluminum phosphide) grown on a GaAs substrate. When forward biased, electrons recombine with holes in the active region, releasing photons with energy corresponding to the bandgap. The yellow emission (585-595nm) is achieved through careful control of the aluminum and indium fractions. The narrow spectral width (15nm) indicates high material quality and well-optimized epitaxial layers. The wide radiation pattern results from the chip geometry and transparent substrate design.

13. Industry Trends and Evolution

Yellow SMD LEDs are evolving towards higher efficacy (lm/W) and smaller packages. The 1808 form factor is part of the trend toward miniaturization in consumer electronics. Future developments may include improved thermal management (lower RTHJ-S) and higher ESD ratings. Integration with smart drivers and tunable white/yellow combinations is also growing. The demand for yellow LEDs in automotive (turn signals) and signage continues to drive innovation in brightness and reliability.

This document provides a comprehensive technical reference for the RF-YG1808TS-AC-E0 yellow LED. For detailed binning information and custom configurations, consult your local sales representative.