PLCC-4 Cool White LED Datasheet - Package 3.2x2.8x1.9mm - Voltage 3.1V - Power 0.093W - English Technical Document

1. Product Overview

This document details the specifications for a high-brightness, Cool White Light Emitting Diode (LED) in a PLCC-4 (Plastic Leaded Chip Carrier) surface-mount package. The primary design focus is on reliability and performance for demanding automotive environments, specifically targeting exterior lighting applications. Its core advantages include a wide viewing angle, robust construction for harsh conditions, and compliance with stringent automotive and environmental standards.

2. In-Depth Technical Parameter Analysis

2.1 Photometric and Electrical Characteristics

The device operates at a typical forward current (I_F) of 30 mA. Under this condition, it delivers a typical luminous intensity (I_V) of 3350 millicandelas (mcd), with a minimum of 2240 mcd and a maximum of 5600 mcd. The typical forward voltage (V_F) is 3.10 volts, ranging from 2.75V to 3.75V. The dominant wavelength is characterized by CIE 1931 chromaticity coordinates of x=0.33 and y=0.34, defining its Cool White color point. The spatial light distribution is defined by a wide 120-degree viewing angle (2θ_½), providing broad illumination.

2.2 Absolute Maximum Ratings and Thermal Management

Critical limits must not be exceeded to ensure device longevity. The absolute maximum continuous forward current is 60 mA, with a surge current capability of 250 mA for pulses ≤10 μs. The maximum power dissipation is 225 mW. The junction temperature (T_J) must not exceed 125°C, with an operating temperature range of -40°C to +110°C. Thermal management is crucial; the thermal resistance from junction to solder point (R_thJS) is specified with a maximum of 150 K/W (real) and 100 K/W (electrical). Proper PCB thermal design is necessary to maintain T_J within safe limits.

3. Performance Curve Analysis

3.1 Forward Current vs. Voltage (I-V Curve)

The I-V graph shows the relationship between forward current and voltage at 25°C. The curve is typical for a semiconductor diode, exhibiting an exponential rise. Designers use this to calculate series resistor values or driver circuit requirements to achieve the desired operating current.

3.2 Relative Luminous Intensity vs. Forward Current

This graph illustrates that light output increases with current but exhibits a sub-linear relationship at higher currents, primarily due to increased junction temperature and efficiency droop. The output is normalized to its value at 30 mA.

3.3 Temperature Dependence

Two key graphs show performance variation with junction temperature (T_J) at a constant 30 mA drive current. The Relative Luminous Intensity vs. Junction Temperature curve demonstrates a decrease in light output as temperature increases, a common characteristic of LEDs. The Relative Forward Voltage vs. Junction Temperature curve shows a negative temperature coefficient, where V_F decreases linearly with rising T_J. This property can sometimes be used for temperature sensing.

3.4 Chromaticity Shift

Graphs plotting ΔCIE x and ΔCIE y against both forward current and junction temperature show the stability of the white color point. Minor shifts occur, which are important for applications requiring consistent color appearance.

3.5 Forward Current Derating

A critical graph for reliability, the derating curve plots the maximum permissible continuous forward current against the solder pad temperature (T_S). As T_S increases, the allowable I_F must be reduced to prevent exceeding the maximum junction temperature. For example, at T_S=110°C, the maximum I_F is 31 mA. The device should not be operated below 8 mA.

3.6 Permissible Pulse Handling

This graph defines the maximum permissible surge current (I_F(AV)) for a given pulse width (t_p) and duty cycle (D). It allows designers to understand the LED's capability for pulsed operation, such as in PWM dimming or signaling applications.

3.7 Spectral Distribution

The relative spectral power distribution graph shows the emitted light intensity across wavelengths, typical for a phosphor-converted white LED, with a blue pump peak and a broader yellow phosphor emission band.

4. Binning System Explanation

4.1 Luminous Intensity Binning

The product is sorted into bins based on measured luminous intensity at 30 mA. The binning structure is extensive, ranging from code L1 (11.2-14 mcd) to GA (18000-22400 mcd). For this specific variant, the possible output bins are highlighted, with the typical value of 3350 mcd falling within the CA bin (2800-3550 mcd). This allows designers to select parts with consistent brightness levels.

4.2 Color (Chromaticity) Binning

The Cool White color point is controlled within specific quadrangles on the CIE 1931 chromaticity diagram. The datasheet defines bins like 64A, 64B, 64C, 64D, 60A, and 60B, each with a set of four (x,y) coordinate pairs that form the corners of the allowable color region. The correlated color temperature (CCT) reference range for these bins is between 6240K and 6680K, confirming the cool white appearance. This ensures color uniformity in multi-LED applications.

5. Mechanical and Package Information

The device uses a standard PLCC-4 surface-mount package. While exact dimensions are not provided in the extracted text, typical PLCC-4 packages have a footprint of approximately 3.2mm x 2.8mm with a height around 1.9mm. The package includes a thermal pad to aid in heat dissipation. Polarity is indicated by the shape of the package or a marked cathode. The recommended soldering pad layout is provided to ensure reliable solder joints and optimal thermal performance.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

The LED is rated for reflow soldering with a peak temperature of 260°C for a maximum of 30 seconds. This is compatible with standard lead-free (Pb-free) reflow processes. A typical reflow profile with preheat, soak, reflow, and cooling stages should be followed, ensuring the temperature at the LED leads does not exceed the specified limit.

6.2 Precautions for Use

General handling precautions include using appropriate ESD protection during assembly, as the device has an ESD sensitivity of 8 kV (HBM). Avoid applying mechanical stress to the lens. The product is not designed for reverse voltage operation. Storage should be in a dry, controlled environment, adhering to the Moisture Sensitivity Level (MSL) 3 requirements, which typically mandate baking if the package is exposed to ambient air for longer than 168 hours before soldering.

7. Reliability and Compliance

This LED is qualified to the AEC-Q102 standard, which is the key reliability stress test specification for discrete optoelectronic semiconductors in automotive applications. It also features sulfur robustness rated at A1 level, providing resistance against corrosive atmospheres containing sulfur gases, which is critical for automotive and industrial environments. The product complies with RoHS (Restriction of Hazardous Substances), EU REACH regulations, and is Halogen-Free (Br<900ppm, Cl<900ppm, Br+Cl<1500ppm).

8. Application Suggestions

8.1 Primary Application: Automotive Exterior Lighting

The stated primary application is automotive exterior lighting. This includes functions such as daytime running lights (DRLs), position lights, side marker lights, turn signal indicators, and interior lighting. The wide viewing angle, high brightness, and automotive-grade reliability (AEC-Q102, wide temperature range) make it suitable for these tasks.

8.2 Design Considerations

Thermal Design: Effective heat sinking via the PCB is paramount. Use the recommended pad layout, connect the thermal pad to a copper pour, and consider using thermal vias to inner or bottom layers. Monitor the solder point temperature (T_S) to stay within the derating curve limits.
Current Drive: A constant current driver is recommended over a constant voltage source with a series resistor for better stability and longevity, especially over the wide automotive temperature range. Implement appropriate inrush current protection.
Optical Design: The 120-degree viewing angle may require secondary optics (lenses, reflectors) to shape the beam for specific applications like signaling.

9. Technical Comparison and Differentiation

Compared to generic commercial-grade LEDs, this device's key differentiators are its automotive qualification (AEC-Q102) and sulfur robustness (A1). These are not typical features of consumer LEDs and are essential for surviving the thermal cycles, vibration, humidity, and chemical exposures found in vehicles. The guaranteed wide operating temperature range (-40°C to +110°C) also exceeds that of standard parts. The detailed binning structure for both intensity and color provides a higher level of consistency for applications requiring uniform appearance.

10. Frequently Asked Questions (FAQ)

Q: What is the purpose of the thermal pad?
A: The thermal pad provides a low-resistance path for heat to flow from the LED junction to the printed circuit board (PCB). This is critical for managing junction temperature, which directly affects light output, color stability, and long-term reliability.

Q: Can I drive this LED with a 12V automotive battery directly?
A: No. The typical forward voltage is ~3.1V. Connecting it directly to 12V would cause catastrophic overcurrent. You must use a current-limiting circuit, such as a series resistor calculated for the worst-case V_F and battery voltage, or preferably, a dedicated constant-current LED driver.

Q: What does MSL 3 mean for storage?
A: Moisture Sensitivity Level 3 indicates that the sealed packaging can be stored in a factory ambient environment (<30°C/60% RH) for up to 168 hours (7 days) after the bag is opened. If exposed longer, the parts must be baked at 125°C for 24 hours before reflow to prevent "popcorning" damage during soldering.

Q: How stable is the white color over temperature and current?
A: Refer to the "Chromaticity Coordinates Shift" graphs. While shifts occur (Δx, Δy), they are relatively small within the specified operating ranges. For most automotive exterior applications, this shift is acceptable. For critical color-matching applications, consult the detailed binning data.

11. Design and Usage Case Study

Scenario: Designing a Daytime Running Light (DRL) Module.
A designer is creating a compact DRL module for a car. They select this LED for its brightness, wide angle, and AEC-Q102 compliance. The module uses 6 LEDs in series. The design process involves:
1. Electrical Design: Calculating the required driver output voltage (6 * ~3.1V = ~18.6V plus headroom). Selecting a buck-boost or boost LED driver IC that can operate from the vehicle's 9-16V system and provide a constant 30mA (or slightly less for margin) to the string.
2. Thermal Design: Designing a 2-layer PCB with a large top-layer copper area under the LED thermal pads, connected through multiple thermal vias to a bottom-layer copper plane acting as a heat spreader. Thermal simulation is run to ensure T_S stays below 85°C at the highest ambient temperature (e.g., 70°C under-hood).
3. Optical/Mechanical Design: Designing an injection-molded polycarbonate lens to collimate the 120-degree emission into a specific DRL beam pattern as per regulatory standards. The lens also provides environmental sealing (IP67).
This case highlights the interdependence of electrical, thermal, and optical design when using high-performance LEDs.

12. Operating Principle Introduction

This is a phosphor-converted white LED. At its core is a semiconductor chip (typically based on indium gallium nitride - InGaN) that emits blue light when forward biased (electrons and holes recombine in the p-n junction, releasing energy as photons). A portion of this blue light is absorbed by a layer of yellow-emitting phosphor (often cerium-doped yttrium aluminum garnet - YAG:Ce) deposited on or near the chip. The mixture of the remaining blue light and the converted yellow light produces the perception of white light. The exact ratio of blue to yellow determines the correlated color temperature (CCT), resulting in a "Cool White" appearance in this case.

13. Technology Trends

The trend in automotive LED lighting is towards higher efficiency (more lumens per watt), higher power density, and improved reliability at elevated temperatures. There is also a move towards smarter integration, with LEDs incorporating driver ICs and sensors (for temperature monitoring) into the package. Furthermore, the demand for precise and stable color rendering, especially for advanced forward lighting systems and interior ambient lighting, is increasing. The sulfur robustness feature highlighted in this datasheet is becoming a more common requirement as pollution and material outgassing in enclosed electronic modules pose greater corrosion risks.