SMD Mid-Power LED 67-22ST Datasheet - PLCC-2 Package - 65mA - 2.9V Max - White Light - English Technical Documentation

1. Product Overview

The 67-22ST series represents a family of SMD (Surface-Mount Device) Mid-Power LEDs packaged in the industry-standard PLCC-2 (Plastic Leaded Chip Carrier) form factor. These components are engineered to deliver high-efficacy white light output, making them suitable for a broad spectrum of general and decorative lighting applications. The core design philosophy centers on achieving an optimal balance between luminous performance, energy efficiency, reliability, and cost-effectiveness.

The LED utilizes InGaN (Indium Gallium Nitride) chip technology encapsulated in a water-clear resin. This combination is responsible for generating the white light emission. The package is characterized by a compact footprint and a wide viewing angle, typically 120 degrees, which facilitates uniform light distribution. A key feature of this series is its compliance with modern environmental and safety standards, including being Pb-free (lead-free), RoHS compliant, REACH compliant, and meeting halogen-free requirements (Br<900ppm, Cl<900ppm, Br+Cl<1500ppm).

The primary target markets for this LED include general ambient lighting, decorative and architectural lighting, entertainment lighting, backlighting for indicators, and various illumination tasks where consistent, high-quality white light is required. Its form factor and performance parameters align well with integration into LED strips, modules, light panels, and retrofit bulbs.

2. In-Depth Technical Parameter Analysis

This section provides a detailed breakdown of the critical parameters that define the LED's operational boundaries and performance under standard conditions (Tsoldering = 25°C).

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. Operation under or at these limits is not guaranteed and should be avoided in reliable design.

• Forward Current (IF): 180 mA (Continuous).
• Peak Forward Current (IFP): 300 mA (Pulsed, Duty Cycle 1/10, Pulse Width 10ms). This rating is crucial for designs involving PWM (Pulse Width Modulation) dimming.
• Power Dissipation (Pd): 522 mW. This is the maximum power the package can dissipate without exceeding its thermal limits.
• Operating Temperature (Topr): -40°C to +85°C. The device is rated for operation in a wide ambient temperature range.
• Storage Temperature (Tstg): -40°C to +100°C.
• Thermal Resistance (RθJ-S): 21 °C/W (Junction to Soldering point). This is a critical parameter for thermal management design. It indicates that for every watt of power dissipated, the junction temperature will rise 21°C above the solder point temperature.
• Maximum Junction Temperature (Tj): 115°C. The semiconductor junction must not exceed this temperature.
• Soldering Temperature: Reflow soldering is specified at 260°C for a maximum of 10 seconds. Hand soldering is allowed at 350°C for a maximum of 3 seconds. These limits must be strictly adhered to during PCB assembly.

Important Note: These LEDs are sensitive to Electrostatic Discharge (ESD). Proper ESD handling procedures (use of grounded wrist straps, conductive mats, etc.) must be followed during assembly and handling.

2.2 Electro-Optical Characteristics

These parameters define the typical performance of the LED when operated at its nominal forward current of 65mA.

• Luminous Flux (Φ): The minimum luminous output varies by product variant (Correlated Color Temperature - CCT), ranging from 36 lm to 39 lm as listed in the mass production table. A typical tolerance of ±11% applies.
• Forward Voltage (VF): Maximum value is 2.9V at 65mA, with a typical tolerance of ±0.1V. The actual VF is binned (see Section 3).
• Color Rendering Index (CRI - Ra): Minimum value is 80 for the "K" bin code, with a tolerance of ±2. The R9 value (saturation of red) is specified as a minimum of 0.
• Viewing Angle (2θ1/2): Typically 120 degrees. This is the full angle at which the luminous intensity drops to half of its peak value.
• Luminous Efficacy: Typical efficacy is up to 225 lm/W for specific variants (e.g., 4000K, 5000K), calculated under the condition of 65mA forward current.
• Reverse Current (IR): Maximum of 50 µA when a reverse voltage (VR) of 5V is applied.

3. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into bins. The 67-22ST series uses a comprehensive binning system for key parameters.

3.1 Color Rendering Index (CRI) Binning

The product number includes a code for CRI. For this series, the code "K" is used, which corresponds to a minimum CRI (Ra) of 80.

3.2 Luminous Flux Binning

Luminous flux is binned according to the CCT of the LED. The bin code (e.g., 36L2, 39L2) defines a minimum and maximum flux range in lumens.

• 2700K: Bins include 36L2 (36-38 lm), 38L2 (38-40 lm), 40L2 (40-42 lm).
• 3000K/3500K: Bins include 38L2 (38-40 lm), 40L2 (40-42 lm), 42L2 (42-44 lm).
• 4000K/5000K/5700K/6500K: Bins include 39L2 (39-41 lm), 41L2 (41-43 lm), 43L2 (43-45 lm).

The tolerance on luminous flux is ±11%.

3.3 Forward Voltage (VF) Binning

Forward voltage is grouped and binned to aid in circuit design for consistent current drive. The bin code is part of the product number (e.g., "29" in 5M403929U6).

• Group 2629: This group includes bins 26A (2.6-2.7V), 27A (2.7-2.8V), and 28A (2.8-2.9V). The product number example uses the upper limit of this group, 2.9V max.

The tolerance on forward voltage is ±0.1V.

3.4 Chromaticity (Color) Binning

The LEDs are binned within a 5-step MacAdam ellipse for each Correlated Color Temperature (CCT). This ensures that all LEDs of the same ordered CCT (2700K, 3000K, 3500K, 4000K, 5000K, 5700K, 6500K) will appear visually consistent in color, as they fall within a very small area on the CIE 1931 chromaticity diagram. The provided table lists the target Cx, Cy coordinates and ellipse parameters (a, b, theta) for each CCT step. The tolerance for chromaticity coordinates is ±0.01.

4. Performance Curve Analysis

The datasheet provides several graphs illustrating the relationship between key parameters. Understanding these is vital for robust system design.

4.1 Forward Voltage Shift vs. Junction Temperature (Fig. 1)

This curve shows that the forward voltage (VF) of the LED decreases linearly as the junction temperature (Tj) increases. This is a characteristic of semiconductor diodes. For thermal management or constant-current drive design, this negative temperature coefficient must be considered to avoid thermal runaway if using a constant-voltage source.

4.2 Relative Luminous Intensity vs. Forward Current (Fig. 2)

The light output is not linearly proportional to current. While output increases with current, the relationship tends to sub-linear at higher currents due to efficiency droop and increased thermal effects. Operating significantly above the nominal 65mA will yield diminishing returns in light output per watt and will generate more heat.

4.3 Relative Luminous Flux vs. Junction Temperature (Fig. 3)

This is one of the most critical curves. It demonstrates the reduction in light output as the LED junction temperature rises. High junction temperatures directly lead to lower efficacy (lumens per watt) and accelerated lumen depreciation (shorter lifespan). Effective heat sinking is paramount to maintain performance and longevity.

4.4 Forward Current vs. Forward Voltage (Fig. 4)

This is the classic I-V (Current-Voltage) curve for a diode. It shows the exponential relationship. For a constant current driver set to 65mA, the voltage across the LED will be approximately 2.9V or less, depending on the specific VF bin and temperature.

4.5 Maximum Driving Current vs. Soldering Temperature (Fig. 5)

This graph defines the derating of the maximum allowable forward current based on the temperature at the soldering point (Ts). As Ts increases, the maximum safe operating current must be reduced to prevent the junction temperature from exceeding its 115°C limit. This chart is essential for designing applications that operate in high ambient temperatures.

4.6 Radiation Diagram (Fig. 6)

This polar plot visually represents the spatial distribution of light intensity. The 67-22ST exhibits a Lambertian or near-Lambertian distribution pattern, typical for PLCC packages with a dome lens, resulting in the wide 120-degree viewing angle.

4.7 Spectrum Distribution

The datasheet includes a spectral power distribution graph (wavelength vs. relative intensity). This shows the LED's emission profile across the visible spectrum. For white LEDs, this is typically a blue peak (from the InGaN chip) combined with a broader yellow phosphor emission. The shape of this curve directly influences the Color Rendering Index (CRI) and the perceived quality of the white light.

5. Application Guidelines and Design Considerations

5.1 Electrical Drive

Constant Current Drive is Mandatory: LEDs are current-driven devices. A constant current (CC) driver is strongly recommended to ensure stable light output and prevent thermal runaway. The nominal drive current is 65mA. While the absolute maximum is 180mA, operation above the nominal current will reduce efficacy and lifespan. For dimming, PWM (Pulse Width Modulation) is the preferred method as it maintains color consistency.

5.2 Thermal Management

This is the single most important factor for reliability and performance.

• Heat Sinking: The PCB must act as an effective heat sink. Use a board with sufficient copper area (copper pour) connected to the LED's thermal pad (soldering points).
• Thermal Path: Minimize the thermal resistance from the LED junction to the ambient environment. The RθJ-S of 21°C/W is the resistance from the junction to your board's solder point. You must add the resistance from the board to ambient.
• Calculation: Estimate Tj using: Tj = Ts + (Pd * RθJ-S), where Ts is the measured temperature at the solder point on the PCB. Ensure Tj remains well below 115°C under all operating conditions.

5.3 Optical Integration

The wide 120-degree beam angle is suitable for applications requiring diffuse, even illumination. For more focused beams, secondary optics (lenses, reflectors) will be required. The water-clear resin package is compatible with most common optical materials.

6. Comparison and Differentiation

The 67-22ST series positions itself within the competitive mid-power LED market through several key attributes:

• Balanced Performance: It offers a strong combination of efficacy (up to 225 lm/W typ.), good CRI (80 min.), and a wide CCT range, making it a versatile general-purpose component.
• Standardized Package: The PLCC-2 package is ubiquitous, ensuring broad compatibility with existing manufacturing processes, pick-and-place equipment, and optical systems.
• Comprehensive Binning: The detailed binning for flux, voltage, and chromaticity (5-step MacAdam ellipse) provides designers with the predictability needed for consistent end-product quality, especially in multi-LED arrays.
• Environmental Compliance: Full compliance with RoHS, REACH, and halogen-free standards future-proofs designs for global markets with stringent regulations.

7. Frequently Asked Questions (FAQs)

7.1 Can I drive this LED with a constant voltage source?

It is not recommended. The negative temperature coefficient of VF can lead to thermal runaway if driven by a constant voltage. A constant current driver is essential for stable and safe operation.

7.2 What is the meaning of the "U6" in the part number?

"U6" is the forward current index, specifying the nominal operating forward current (IF) of 65mA.

7.3 The datasheet lists a minimum R9 of 0. What does this imply for color quality?

An R9 value of 0 indicates that this LED does not guarantee enhanced rendering of deep red tones. While it meets the general CRI Ra requirement of 80+, applications where accurate rendering of reds is critical (e.g., retail lighting for meat or produce) may require LEDs with a higher specified R9 value (e.g., >50).

7.4 How many LEDs can I connect in series?

The number depends on your driver's output voltage compliance range. With a maximum VF of 2.9V per LED at 65mA, a 24V driver could theoretically drive about 8 LEDs in series (8 * 2.9V = 23.2V), leaving some headroom. Always account for voltage tolerances and temperature effects.

8. Practical Design Example

Scenario: Designing a linear LED module for under-cabinet lighting with 10 LEDs, CCT 4000K, driven at 65mA.

1. Part Selection: Choose 67-22ST/KKX-5M403929U6/2T. This specifies: CRI 80+ (K), CCT 4000K (4039), Min. Flux 39 lm (39), Max VF 2.9V (29), Current 65mA (U6).
2. Electrical Design: Select a constant current driver with an output of 65mA. The driver's output voltage range must cover at least 10 * (VF min) to 10 * (VF max) = ~26V to 29V, plus margin.
3. Thermal Design: Use an aluminum-core PCB (MCPCB) or a standard FR4 PCB with a large, unbroken copper plane on the top layer connected to the LED pads. Ensure the fixture housing provides a path for heat dissipation.
4. Optical Design: For diffuse lighting, the LEDs can be used bare. For a more uniform appearance, a diffuser cover can be placed over the array.
5. Expected Performance: Total luminous flux will be approximately 10 * [39 to 41 lm] = 390 to 410 lm (minimum, based on bin), with a system efficacy heavily dependent on the thermal design and driver efficiency.