LED 3.2x1.25x1.1mm Green 3.0V 105mW Specification - Technical Datasheet and Design Guide

1. Product Overview

This green SMD LED is designed for general optical indication and display applications. It features a compact 3.2mm x 1.25mm x 1.1mm package (standard PLCC-2 footprint) and utilizes a high-efficiency green chip. The LED offers a wide viewing angle of 140 degrees, making it suitable for backlighting and indicator uses. With a maximum power dissipation of 105mW and a forward current rating of 30mA, it provides reliable performance over an operating temperature range of -40°C to +85°C. The device is RoHS compliant and has a moisture sensitivity level of 3 (MSL-3).

2. Technical Parameters - In-Depth Analysis

2.1 Electrical and Optical Characteristics (at Ts=25°C, IF=20mA)

The LED is characterized under a forward current of 20mA. Key parameters include:

• Forward Voltage (VF): The device is available in multiple voltage bins: G1 (2.8-2.9V), G2 (2.9-3.0V), H1 (3.0-3.1V), H2 (3.1-3.2V), I1 (3.2-3.3V), I2 (3.3-3.4V), J1 (3.4-3.5V). The typical VF for the middle bin (H1) is 3.0V. This binning allows designers to select the exact voltage for series resistor optimization or current matching.
• Dominant Wavelength (λD): The green emission is centered around 520nm, with bins D20 (517.5-520nm), E10 (520-522.5nm), E20 (522.5-525nm), F10 (525-527.5nm), F20 (527.5-530nm). This tight wavelength control ensures consistent color appearance across production lots.
• Luminous Intensity (IV): Multiple brightness bins are specified: 1AU (260-330mcd), 1AV (330-430mcd), 1CG (430-560mcd), 1CL (560-700mcd), 1CM (700-900mcd). The highest bin (1CM) provides excellent luminous output for high-visibility applications.
• Spectral Half Bandwidth: 30nm (typical), indicating a relatively pure green color.
• Viewing Angle (2θ1/2): 140 degrees, enabling wide illumination coverage.
• Reverse Current (IR): Maximum 10μA at VR=5V, ensuring low leakage in reverse bias.
• Thermal Resistance (RTHJ-S): 450°C/W (typical), important for thermal management in high-power designs.

2.2 Absolute Maximum Ratings

The LED must not be operated beyond these limits to prevent damage:

• Power Dissipation (Pd): 105mW
• Forward Current (IF): 30mA (continuous)
• Peak Forward Current (IFP): 60mA (pulse, 1/10 duty, 0.1ms pulse width)
• ESD (HBM): 1000V
• Operating Temperature (Topr): -40°C ~ +85°C
• Storage Temperature (Tstg): -40°C ~ +85°C
• Junction Temperature (Tj): 95°C

Care must be taken to ensure that the power dissipation does not exceed the maximum rating. The forward current should be derated based on actual junction temperature, which should remain below 95°C.

3. Binning System Explanation

The LED is binned according to three parameters: forward voltage (VF), dominant wavelength (λD), and luminous intensity (IV). This allows customers to order tightly specified parts for consistent performance in arrays or backlight units.

Voltage Bins: G1, G2, H1, H2, I1, I2, J1. Each bin covers a 0.1V range, enabling precise current regulation.

Wavelength Bins: D20, E10, E20, F10, F20. Each bin covers 2.5nm, ensuring color consistency within a production batch.

Intensity Bins: 1AU, 1AV, 1CG, 1CL, 1CM. These bins span from 260mcd to 900mcd, covering a wide range of brightness requirements.

4. Performance Curves Analysis

4.1 Forward Voltage vs. Forward Current

The typical I-V curve shows that at IF=20mA, VF is around 3.0V. As current increases, voltage rises nonlinearly. At high currents, careful thermal management is necessary due to self-heating.

4.2 Forward Current vs. Relative Intensity

Relative luminous intensity increases with forward current but not linearly due to junction heating. At IF=30mA, the intensity is approximately 1.5 times that at IF=20mA (based on typical curve).

4.3 Pin Temperature vs. Relative Intensity and Forward Current

As the LED heats up, relative intensity decreases. The thermal resistance of 450°C/W means that at 20mA, the junction temperature rise above ambient is modest. However, at maximum current and ambient temperature, the junction can approach the 95°C limit, requiring heatsinking or derating.

4.4 Forward Current vs. Dominant Wavelength

The dominant wavelength shifts slightly with current. Typically, green LEDs exhibit a small blue shift at higher currents. The drift is within a few nanometers, which is acceptable for most indicator applications.

4.5 Relative Intensity vs. Wavelength

The spectral distribution shows a single peak around 520nm with a half-width of 30nm, confirming a pure green emission. No secondary peaks are present.

4.6 Radiation Pattern

The LED emits with a lambertian-like distribution, with intensity dropping to half at 70° from the optical axis. This wide beam makes it ideal for backlighting or signage.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED is housed in a 3.20mm x 1.25mm x 1.10mm package. The top view shows a rectangular shape with two terminals (anode and cathode) as marked. The bottom view indicates the pad layout: a 1.20mm x 0.60mm pad for terminal 1 (cathode) and a 1.20mm x 0.45mm pad for terminal 2 (anode). The recommended solder pad pattern is 5.00mm x 2.00mm for proper heat dissipation and mechanical stability. Polarity is indicated by a marker on the package.

5.2 Polarity and Soldering Patterns

The polarity marking is shown in Fig.1-4. The cathode is usually indicated by a notch or dot. The recommended soldering pattern (Fig.1-5) ensures good thermal and electrical connection. All dimensions have a tolerance of ±0.2mm unless noted.

6. Soldering and Assembly Guidelines

6.1 SMT Reflow Soldering Profile

The standard reflow profile (based on JEDEC J-STD-020) includes:

• Preheat: 150°C to 200°C for 60-120 seconds
• Time above 217°C (TL): 60-150 seconds
• Peak temperature (TP): 260°C, with maximum 10 seconds above 255°C
• Cooling: 6°C/s max
• Total time from 25°C to peak: maximum 8 minutes

Reflow soldering should not exceed two passes. If more than 24 hours elapse between passes, the LED may absorb moisture and be damaged. Baking at 60±5°C for 24 hours is recommended if storage conditions are exceeded.

6.2 Hand Soldering and Rework

Manual soldering with a soldering iron should be limited to 300°C for less than 3 seconds. Only one rework is allowed. For rework, a dual-head soldering iron is recommended to avoid thermal stress.

6.3 Handling Precautions

Avoid mounting on warped PCBs. Do not apply mechanical force during or after soldering. Rapid cooling after soldering is not allowed. The LED is ESD sensitive (Class 1, 1000V HBM), so proper ESD protection must be used during handling and assembly.

7. Packaging and Ordering Information

7.1 Tape and Reel Packaging

The LEDs are supplied in carrier tape with 3000 pieces per reel (7-inch diameter). Tape dimensions: width 8.00mm, pitch 4.00mm. The reel has a diameter of 178mm, hub diameter 60mm, and spindle hole 13.0mm. A label includes part number, spec number, lot number, bin code (for flux, chromaticity, voltage, wavelength), quantity, and date code.

7.2 Moisture Barrier Bag and Box

Each reel is sealed in a moisture barrier bag with a desiccant and humidity indicator card. The bag is then packed in a cardboard box for shipping. Storage conditions: before opening bag, store at ≤30°C and ≤75% RH for up to 1 year. After opening, use within 168 hours at ≤30°C and ≤60% RH. Baking at 60±5°C for ≥24 hours is required if the moisture indicator shows exposure or the storage time is exceeded.

8. Application Recommendations

8.1 Typical Applications

• Optical indicators on electronic devices (e.g., status LEDs, pushbutton backlight)
• Switch and symbol backlighting in automotive or consumer products
• General signage and display backlighting
• Decorative lighting where compact size and wide angle are required

8.2 Design Considerations

• Current Limiting: Always use a series resistor to limit current to ≤30mA. Without a resistor, slight voltage variations can cause large current changes and damage.
• Thermal Management: For maximum current or high ambient temperature, consider PCB copper area for heatsinking. The thermal resistance of 450°C/W requires careful layout to keep junction temperature below 95°C.
• Environmental Protection: Avoid exposure to sulfur compounds (>100PPM), bromine (>900PPM), chlorine (>900PPM), and VOCs that may outgas from adhesives or potting materials. These can cause discoloration and light output degradation.
• Parallel Operation: If multiple LEDs are used in parallel, each should have its own series resistor to balance current.

9. Technical Comparison

Compared to standard green LEDs in similar PLCC-2 packages, this device offers a wide viewing angle (140°) and multiple brightness bins up to 900mcd. The tight wavelength binning (±2.5nm per bin) ensures superior color consistency, which is critical for multi-LED assemblies. The low thermal resistance of 450°C/W (typical) is competitive for a 3.2x1.25mm package, enabling higher drive currents when properly heatsinked. Additionally, the MSL-3 rating and RoHS compliance make it suitable for automated SMT assembly.

10. Frequently Asked Questions

Q1: What is the recommended operating current for this LED?
A: The typical test current is 20mA, providing a good balance between brightness and thermal margin. The absolute maximum continuous current is 30mA, but the junction temperature must be kept below 95°C.

Q2: Can I use this LED in a pulse-width modulation (PWM) application?
A: Yes, the peak current can be up to 60mA with a duty cycle of 1/10 and pulse width of 0.1ms. For higher duty PWM, ensure average current ≤30mA.

Q3: How do I select the correct voltage bin for my design?
A: If you need a tight voltage range for current mirroring or series connection, choose a specific bin (e.g., H1 for 3.0-3.1V). For general use, the typical 3.0V (H1) is recommended.

Q4: What is the storage life after opening the moisture barrier bag?
A: 168 hours at ≤30°C and ≤60% RH. If not used within this time, bake at 60±5°C for at least 24 hours before reflow.

Q5: Can I use this LED outdoors?
A: The operating temperature range is -40°C to +85°C, suitable for many outdoor applications. However, the device is not rated for direct water exposure; additional conformal coating may be needed.

11. Practical Design Example

Example: Backlighting a pushbutton switch with two LEDs in parallel.

• Desired brightness: approximately 500mcd per LED (using bin 1CG or 1CL).
• Supply voltage: 5V DC.
• LED forward voltage (typical): 3.0V at 20mA.
• Series resistor: R = (5V - 3.0V) / 0.04A (two LEDs in parallel, each 20mA) = 50Ω. Choose 51Ω, 1/4W resistor.
• Thermal check: At 25°C ambient, junction temperature rise = 20mA * 3.0V * 450°C/W = 0.027W * 450 = 12.15°C. Junction temp = 37.15°C, well below 95°C. Even at 85°C ambient, junction = 97.15°C, slightly over; consider using a larger pad area to reduce thermal resistance or reduce current to 18mA.

12. Principles of Operation

The LED is a p-n junction diode made from gallium nitride (GaN) or related III-V compound semiconductor materials that emit green light when forward biased. The energy bandgap determines the wavelength. In this case, the dominant wavelength around 520nm corresponds to a bandgap of approximately 2.38eV. The device is encapsulated in a transparent silicone or epoxy that provides optical extraction and mechanical protection. The wide viewing angle is achieved by a diffusing encapsulant or a package design that spreads the emitted light.

13. Development Trends

Green LEDs continue to improve in efficiency (lm/W) due to better epitaxial growth techniques and chip designs. Future trends for SMD LEDs in this footprint include higher luminous efficacy, reduced thermal resistance, and tighter wavelength bins for better color mixing in RGB applications. Additionally, the integration of ESD protection chips within the package is becoming more common to improve robustness. The demand for miniaturized, high-brightness LEDs for wearable and IoT devices is driving further innovations in packaging and thermal management.