LTW-206DCG-TMS White PLCC LED Datasheet - 3.0x2.8x1.9mm - 3.1V - 120mW - English Technical Document

1. Product Overview

The LTW (LiteOn White PLCC LED) series represents an energy-efficient and ultra-compact light source. It merges the long lifetime and high reliability inherent to Light Emitting Diodes with brightness levels competitive with conventional lighting technologies. This product offers significant design flexibility and high luminous output, enabling new opportunities for solid-state lighting to replace traditional light sources in various applications.

1.1 Key Features

• High-power LED light source.
• Instantaneous light output (response time less than 100 nanoseconds).
• Low voltage DC operation.
• Low thermal resistance package.
• Compliant with RoHS (Restriction of Hazardous Substances) directives.
• Compatible with lead-free reflow soldering processes.

1.2 Target Applications

This LED is suitable for a broad range of illumination purposes, including but not limited to:

• Reading lights for automotive, bus, and aircraft interiors.
• Portable lighting such as flashlights and bicycle lights.
• Downlighters and orientation lighting.
• Decorative and entertainment lighting.
• Bollard, security, and garden lighting.
• Cove, undershelf, and task lighting.
• Traffic signaling, beacons, and rail crossing/wayside lights.
• Indoor and outdoor commercial and residential architectural lighting.
• Edge-lit signs (e.g., exit signs, point-of-sale displays).

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation at or beyond these limits is not advised.

• Power Dissipation: 120 mW. This is the maximum power the package can dissipate as heat under specified conditions.
• Peak Forward Current: 100 mA (at 1/10 duty cycle, 0.1ms pulse width). For short pulses, the LED can handle higher current than its continuous rating.
• DC Forward Current: 30 mA. The maximum recommended continuous forward current for reliable long-term operation.
• Reverse Voltage: 5 V. Exceeding this voltage in reverse bias can cause immediate failure.
• Operating Temperature Range: -30°C to +85°C. The ambient temperature range for normal device function.
• Storage Temperature Range: -40°C to +100°C.
• Reflow Soldering Condition: Withstands 260°C peak temperature for 10 seconds, compatible with standard lead-free reflow profiles (e.g., per J-STD-020D).

Important Note: Operating the LED under reverse bias conditions in an application circuit may lead to component damage or failure. Proper circuit design to prevent reverse voltage is essential.

2.2 Electro-Optical Characteristics

Measured at Ta=25°C with IF = 20 mA, unless otherwise stated. These are the typical performance parameters.

• Luminous Flux (Φv): Typical value is 9.00 lm, with a minimum of 6.75 lm. This quantifies the total visible light output.
• Luminous Intensity: Typical value is 3100 mcd (millicandela), with a minimum of 2200 mcd. This measures luminous flux per solid angle, relevant for directional brightness.
• Viewing Angle (2θ_1/2): 120 degrees. This is the full angle at which the luminous intensity is half of the peak intensity (at 0°).
• Chromaticity Coordinates (CIE 1931): Typical values are x=0.282, y=0.265. This defines the white point color on the chromaticity diagram. A tolerance of ±0.01 should be applied to these coordinates.
• Forward Voltage (V_F): Typically 3.1 V, with a maximum of 3.1 V and a minimum of 2.7 V at 20 mA.

Measurement Notes: Luminous flux is measured using a sensor/filter combination approximating the CIE photopic eye-response curve. The test standard for chromaticity coordinates and luminous flux is CAS140B. Proper ESD (Electrostatic Discharge) precautions are mandatory during handling to prevent damage.

3. Binning System Explanation

The LED is classified into bins to ensure consistency in key parameters. This allows designers to select parts matching their specific requirements for voltage, flux, and color.

3.1 Forward Voltage (V_F) Binning

LEDs are sorted based on their forward voltage at IF = 20 mA. The binning ensures predictable driver requirements.

• V0: 2.7V - 2.8V
• V1: 2.8V - 2.9V
• V2: 2.9V - 3.0V
• V3: 3.0V - 3.1V

Tolerance on each V_F bin is ±0.05 V.

3.2 Luminous Flux & Intensity Binning

LEDs are binned for both luminous flux (lm) and correlated luminous intensity (mcd) at IF = 20 mA. The intensity value is provided for reference.

• Bins range from 64 (6.75-7.00 lm / 2200-2300 mcd) to 84 (8.75-9.00 lm / 3000-3100 mcd).

Tolerance on each luminous intensity and luminous flux bin is ±10%.

3.3 Color (Chromaticity) Binning

The white light color is tightly controlled through chromaticity coordinate binning on the CIE 1931 diagram. Multiple ranks (e.g., Z1, Z2, A1, A2, B1, B2, C1, C2, etc., with sub-variants) define specific quadrangles on the x,y coordinate plane. This ensures color consistency within a batch. The tolerance for each hue (x, y) bin is ±0.01.

4. Performance Curve Analysis

The datasheet references typical characteristic curves (presumably found on page 6/13). While the specific graphs are not reproduced in the text, standard LED performance trends can be inferred:

• I-V (Current-Voltage) Curve: Would show the exponential relationship between forward current and forward voltage, crucial for driver design.
• Luminous Flux vs. Forward Current: Would illustrate how light output increases with current, typically in a near-linear relationship within the operating range before efficiency droop.
• Luminous Flux vs. Ambient Temperature: Would demonstrate the decrease in light output as the junction temperature rises, highlighting the importance of thermal management.
• Relative Intensity vs. Viewing Angle: Would plot the spatial radiation pattern, confirming the 120-degree viewing angle.
• Spectral Power Distribution: For a white LED (likely phosphor-converted), this would show a broad emission peak in the blue region (from the die) and a broader yellow phosphor emission, combining to produce white light.

5. Mechanical & Package Information

5.1 Outline Dimensions

The LTW-206DCG-TMS is a PLCC (Plastic Leaded Chip Carrier) package. Key dimensions (all in mm, tolerance ±0.1 mm unless noted) include:

• Overall package length: 3.0 mm
• Overall package width: 2.8 mm
• Overall package height: 1.9 mm
• Lead spacing and size as per the detailed drawing.

5.2 Recommended PCB Attachment Pad

A land pattern design is provided for infrared or vapor phase reflow soldering. This ensures proper solder joint formation, thermal transfer, and mechanical stability. The design typically includes thermal relief patterns to manage heat during soldering and operation.

5.3 Polarity Identification

The package includes a polarity indicator (typically a notch or a chamfered corner on the lens or body) to identify the cathode (-) lead. Correct orientation is vital for circuit operation.

6. Soldering & Assembly Guidelines

6.1 Reflow Soldering Parameters

The component is rated for lead-free reflow soldering with a peak temperature of 260°C for 10 seconds. It is recommended to follow a standard reflow profile compliant with J-STD-020D. Preheating stages are critical to minimize thermal shock.

6.2 Cleaning

Unspecified chemical cleaners should not be used as they may damage the plastic package. If cleaning is necessary post-soldering, immersion in ethyl alcohol or isopropyl alcohol at normal temperature for less than one minute is acceptable.

6.3 Storage & Handling

• Moisture Sensitivity: This product is classified as Moisture Sensitivity Level (MSL) 3 per JEDEC J-STD-020. Precautions are required to prevent popcorn cracking during reflow.
• Sealed Package: When stored in its original moisture-proof bag with desiccant, it should be kept at ≤30°C and ≤90% RH. The shelf life is one year from the bag seal date.
• After Bag Opening: Once opened, components should be used within a specified floor life (not explicitly stated but implied for MSL3) or re-baked according to guidelines. Storage should be at ≤30°C and low humidity.
• ESD Protection: The LED is sensitive to electrostatic discharge. Handling must involve anti-static measures (wrist straps, grounded workstations, conductive foam).

7. Packaging & Ordering Information

7.1 Tape and Reel Packaging

The LEDs are supplied on embossed carrier tape and reel for automated assembly.

• Tape Dimensions: Detailed dimensions for pocket pitch, width, and sprocket hole alignment are provided.
• Reel Dimensions: Specifications for standard 7-inch reels are given.
• Packing Quantity: A maximum of 2000 pieces per 7-inch reel. The minimum packing quantity for remainder lots is 500 pieces.
• Quality: The maximum number of consecutive missing components in the tape is two. Packaging complies with EIA-481-1-B specifications.

8. Application Design Considerations

8.1 Thermal Management

Although the package has low thermal resistance, the 120 mW power dissipation must be managed. A properly designed PCB with adequate copper area (using the recommended pad as a heatsink) is necessary to maintain a low junction temperature (Tj). High Tj reduces light output (lumen depreciation), shifts color, and shortens lifetime.

8.2 Current Driving

Use a constant current driver, not a constant voltage source, for stable and predictable light output. The driver should be designed to operate within the Absolute Maximum Ratings (max 30 mA DC). Consider derating the current for high ambient temperature applications to improve reliability.

8.3 Optical Design

The 120-degree viewing angle is suitable for wide-area illumination. For more focused beams, secondary optics (lenses, reflectors) will be required. The small source size makes it compatible with various optical systems.

9. Technical Comparison & Differentiation

While a direct side-by-side comparison with other products is not in the datasheet, key differentiators of this PLCC LED can be inferred:

• High Luminous Intensity: At 3100 mcd typical, it offers high directional brightness for its package size.
• Wide Viewing Angle: The 120-degree angle provides broad, even illumination compared to narrower-angle LEDs.
• Reflow Compatibility: Lead-free reflow soldering compatibility enables cost-effective, high-volume SMT (Surface Mount Technology) assembly.
• Comprehensive Binning: Tight binning on voltage, flux, and color allows for precise and consistent performance in end products.

10. Frequently Asked Questions (Based on Technical Parameters)

10.1 What is the difference between Luminous Flux (lm) and Luminous Intensity (mcd)?

Luminous Flux measures the total amount of visible light emitted in all directions (integrated over a sphere). Luminous Intensity measures how bright the light appears in a specific direction. This LED has high intensity (mcd) due to its package design, even though its total flux (lm) is moderate. The 120-degree beam spreads this intensity over a wide area.

10.2 Can I drive this LED at 30 mA continuously?

Yes, 30 mA is the maximum recommended DC forward current. However, for optimal lifetime and to account for real-world thermal conditions, driving at a lower current (e.g., 20 mA, as used for testing) is often advisable. Always ensure the junction temperature remains within safe limits through proper heatsinking.

10.3 How do I interpret the Chromaticity Coordinate bins?

The bins (Z1, A1, B1, etc.) define small regions on the CIE 1931 color space diagram. Selecting LEDs from the same bin ensures minimal color variation in your application. The provided table gives the x,y coordinate boundaries for each bin. You would typically specify the desired bin code when ordering.

10.4 Is a current-limiting resistor sufficient to drive this LED?

For simple, non-critical applications with a stable DC voltage supply, a series resistor can be used to set the current. However, due to the V_F variation (binning from 2.7V to 3.1V), the current and thus brightness will vary between LEDs. For consistent performance, especially with multiple LEDs or from a variable voltage source (like a battery), a dedicated constant-current LED driver circuit is strongly recommended.

11. Practical Use Case Examples

11.1 Portable Task Light

Scenario: Designing a compact, battery-powered work light.

Implementation: Four LTW-206DCG-TMS LEDs are arranged on a small PCB. They are driven in a 2-series, 2-parallel configuration by a boost converter/constant current driver from a single 3.7V Li-ion battery. The driver is set to ~18 mA per LED to extend battery life while providing ample light. The wide 120-degree beam offers good area coverage on a workbench. The low V_F bin (V0) would be selected to maximize efficiency from the battery.

11.2 Backlight Unit for an Edge-Lit Sign

Scenario: Creating an even backlight for a thin exit sign.

Implementation: Multiple LEDs are placed along one or more edges of an acrylic light guide plate. The high luminous intensity of the LEDs allows them to couple efficiently into the light guide. LEDs from the same tight color bin (e.g., A2) and flux bin (e.g., 82) are used to ensure uniform color and brightness across the sign face. The SMT package allows for a very low-profile assembly.

12. Operating Principle

A Light Emitting Diode (LED) is a semiconductor device that emits light when an electric current passes through it. This phenomenon, called electroluminescence, occurs when electrons recombine with electron holes within the device, releasing energy in the form of photons. The color of the light is determined by the energy band gap of the semiconductor material. The LTW-206DCG-TMS is a white LED, which is typically created by using a blue-emitting semiconductor chip coated with a yellow phosphor. Some of the blue light is converted to yellow by the phosphor, and the mixture of blue and yellow light is perceived as white by the human eye.

13. Technology Trends

The solid-state lighting industry continues to evolve with several clear trends:

• Increased Efficacy: Ongoing development aims to produce more lumens per watt (lm/W), reducing energy consumption for the same light output.
• Improved Color Quality: Advancements in phosphor technology and multi-chip designs lead to higher Color Rendering Index (CRI) values and more consistent color points.
• Miniaturization: Packages continue to shrink while maintaining or increasing light output, enabling ever-smaller and more discreet lighting solutions.
• Smart Integration: LEDs are increasingly combined with control circuitry, sensors, and communication interfaces to create intelligent, connected lighting systems.
• Reliability & Lifetime: Focus remains on enhancing long-term reliability and lumen maintenance, pushing operational lifetimes further beyond traditional lighting.

The LTW-206DCG-TMS, as a high-intensity, reflow-solderable PLCC component, aligns with the trends of miniaturization and compatibility with automated, high-volume manufacturing processes.