LTW-206DCG-TM White PLCC LED Datasheet - Package Dimensions - Forward Voltage 2.7-3.4V - Luminous Flux 7.5-9.5lm - English Technical Document

1. Product Overview

The LTW series represents a compact, energy-efficient light source designed for modern solid-state lighting applications. This product combines the long operational lifetime and reliability inherent to Light Emitting Diodes with a high level of brightness, offering designers a versatile component for displacing conventional lighting technologies. Its ultra-compact form factor provides significant design freedom across a wide range of 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
• RoHS compliant construction
• Compatible with lead-free reflow soldering processes

1.2 Target Applications

This LED is suitable for numerous lighting scenarios, 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; security, garden, and bollard lighting; cove, undershelf, and task lighting; traffic signaling, beacons, and rail crossing lights; various indoor and outdoor commercial and residential architectural lighting; and edge-lit signs for exits or point-of-sale displays.

2. Technical Specifications Deep Dive

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. They are specified at an ambient temperature (Ta) of 25°C.

• Power Dissipation: 120 mW
• Peak Forward Current: 100 mA (under pulsed condition with 1/10 duty cycle and 0.1ms pulse width)
• DC Forward Current: 30 mA
• Reverse Voltage: 5 V
• Operating Temperature Range: -30°C to +85°C
• Storage Temperature Range: -40°C to +100°C
• Reflow Soldering Condition: Withstands 260°C peak temperature for 10 seconds, compliant with lead-free process requirements.

Important Note: Operating the LED under reverse bias conditions in an application circuit may lead to component failure.

2.2 Electro-Optical Characteristics

These key performance parameters are measured at Ta=25°C and a forward current (IF) of 20mA, which is the standard test condition.

• Luminous Flux (Φv): Minimum 7.50 lm, Typical 9.50 lm. This measures the total perceived power of light emitted.
• Luminous Intensity: Minimum 2500 mcd, Typical 3300 mcd. This is the luminous flux per solid angle in a given direction.
• Viewing Angle (2θ1/2): 120 degrees. This defines the angular span where the luminous intensity is at least half of the maximum intensity.
• Chromaticity Coordinates (x, y): Typical values are x=0.282, y=0.265 on the CIE 1931 chromaticity diagram, defining the white point color.
• Forward Voltage (VF): Ranges from 2.7 V to 3.4 V at IF=20mA.

Measurement Notes: Luminous flux is measured using a sensor-filter combo approximating the CIE photopic eye-response curve. The chromaticity coordinates are derived from the CIE 1931 diagram, with testing performed according to the CAS140B standard. A tolerance of +/- 0.01 applies to the chromaticity coordinates.

3. Binning System Explanation

The product is classified into bins to ensure consistency in key parameters. This allows designers to select LEDs matching specific requirements for voltage, light output, and color.

3.1 Forward Voltage (VF) Binning

LEDs are sorted into bins (V0 to V6) based on their forward voltage at 20mA. Each bin has a 0.1V range (e.g., V0: 2.7-2.8V, V1: 2.8-2.9V, etc., up to V6: 3.3-3.4V). A tolerance of +/- 0.1V is maintained within each bin.

3.2 Luminous Flux & Intensity Binning

Light output is binned using a two-digit code (e.g., 73, 74, 81...92). Each code corresponds to a specific range of luminous flux (in lumens) and luminous intensity (in millicandelas). For example, bin 73 covers 7.50-7.75 lm and 2500-2600 mcd. Tolerance on each bin is +/- 10%.

3.3 Color (Chromaticity) Binning

The white color point is tightly controlled through an extensive binning matrix defined by CIE 1931 (x, y) coordinates. Bins are labeled with alphanumeric codes (Z1, Z2, ... C4). Each bin specifies a small quadrilateral area on the chromaticity diagram, ensuring a consistent hue and saturation of white light across production lots. A tolerance of +/- 0.01 applies to each hue bin.

4. Performance Curve Analysis

The datasheet includes typical characteristic curves which are essential for circuit design and thermal management. While specific graph data points are not provided in the text, these curves typically illustrate the relationship between forward current and forward voltage (IV curve), the effect of ambient temperature on luminous flux, and the variation of forward voltage with temperature. Analyzing these curves helps in selecting appropriate current-limiting resistors, predicting light output under different operating conditions, and designing for thermal stability.

5. Mechanical & Package Information

5.1 Outline Dimensions

The LED is housed in a standard PLCC (Plastic Leaded Chip Carrier) surface-mount package. All critical dimensions, including length, width, height, and lead spacing, are provided in millimeter units with a standard tolerance of ±0.1 mm unless otherwise noted. The package features a clear lens for light extraction.

5.2 Recommended PCB Attachment Pad

A land pattern diagram is supplied to guide printed circuit board (PCB) design for reliable soldering. This includes the recommended pad geometry and size for infrared or vapor phase reflow soldering processes, ensuring proper solder joint formation and mechanical stability.

5.3 Polarity Identification

The package includes markings or features (such as a cut corner or a dot) to indicate the cathode (negative) pin, which is crucial for correct orientation during assembly.

6. Soldering & Assembly Guidelines

6.1 Reflow Soldering Profile

A suggested infrared reflow soldering profile is provided, compliant with J-STD-020D for lead-free soldering. The key parameter is the ability to withstand a peak temperature of 260°C for up to 10 seconds. Adhering to this profile is critical to prevent thermal damage to the plastic package and the internal die attach.

6.2 Cleaning

If post-solder cleaning is necessary, only specified chemicals should be used. Unspecified chemicals may damage the package material. It is recommended to immerse the LED in ethyl alcohol or isopropyl alcohol at normal room temperature for a duration not exceeding one minute.

6.3 Storage & Handling

The product is classified as Moisture Sensitivity Level (MSL) 3 per JEDEC J-STD-020. When the moisture-proof bag is sealed, the LEDs should be stored at ≤ 30°C and ≤ 90% Relative Humidity, with a shelf life of one year. Once the bag is opened, the components must be used within a specified timeframe or stored at ≤ 30°C and ≤ 60% RH. Precautions against Electrostatic Discharge (ESD) are mandatory; using wrist straps, anti-static gloves, and ensuring all equipment is properly grounded is recommended.

7. Packaging & Ordering Information

7.1 Tape and Reel Packaging

The LEDs are supplied on embossed carrier tape for automated pick-and-place assembly. Detailed dimensions for both the tape pockets and the reel (7-inch standard) are provided. Specifications include: empty pockets are sealed with cover tape, maximum 2000 pieces per reel, a minimum packing quantity of 500 pieces for remainder lots, and a maximum of two consecutive missing components allowed. Packaging complies with EIA-481-1-B specifications.

8. Application Design Considerations

8.1 Circuit Design

As a low-voltage DC device, a constant current source or a simple current-limiting resistor is required to drive the LED. The design must ensure the operating current does not exceed the maximum DC forward current of 30mA. Calculations must account for the forward voltage bin to set the correct supply voltage and limit resistor value. Heat sinking on the PCB may be necessary for high-current or high-ambient-temperature operation to maintain performance and longevity.

8.2 Thermal Management

Although the package has low thermal resistance, effective heat dissipation is crucial for maintaining luminous output and lifespan. The PCB layout should incorporate adequate copper areas connected to the LED's thermal pad (if applicable) or leads to conduct heat away from the junction.

9. Technical Comparison & Differentiation

Compared to traditional incandescent or fluorescent lighting, this LED offers superior energy efficiency, a much longer operational lifetime (typically tens of thousands of hours), instant on/off capability, and robustness against vibration. Within the LED market, its key advantages include a compact PLCC-2 package, a wide 120-degree viewing angle suitable for area lighting, and a comprehensive binning structure that guarantees consistent color and brightness for applications requiring uniformity.

10. Frequently Asked Questions (FAQ)

Q: What is the typical drive current for this LED?
A: The standard test condition and a common operating point is 20mA DC. It should not exceed 30mA DC continuously.

Q: How do I interpret the bin codes when ordering?
A> You can specify requirements for Forward Voltage (V-bin), Luminous Flux (IV-bin), and Color (e.g., A2, B1). This ensures you receive LEDs with tightly grouped characteristics for your application.

Q: Can I use this LED for outdoor applications?
A: The operating temperature range (-30°C to +85°C) supports many outdoor environments. However, the LED itself is not waterproof or weatherproof; appropriate secondary sealing or housing is required for outdoor use.

Q: Is a heatsink required?
A> For operation at or near the maximum current rating, or in high ambient temperatures, implementing thermal management via PCB copper pours or an external heatsink is strongly recommended to prevent premature light output degradation.

11. Design-in Case Study Example

Scenario: Designing an edge-lit exit sign. Multiple LTW-206DCG-TM LEDs would be placed along the edge of an acrylic light guide. The wide 120-degree viewing angle helps couple light efficiently into the guide. To ensure uniform illumination across the sign face, LEDs from the same luminous flux and color bin should be used. A constant current driver circuit set to 20mA per LED would provide stable operation. The low profile of the PLCC package allows for a slim sign design. Thermal vias in the PCB under the LED pads would help dissipate heat, maintaining brightness over long periods.

12. Operational Principle

This is a white LED based on a semiconductor chip that emits blue light. The blue light passes through a phosphor coating deposited inside the package. The phosphor absorbs a portion of the blue photons and re-emits light across a broader spectrum, primarily in the yellow region. The combination of the remaining blue light and the converted yellow light is perceived by the human eye as white. This technology is known as phosphor-converted white LED.

13. Industry Trends

The solid-state lighting industry continues to focus on increasing luminous efficacy (lumens per watt), improving color rendering index (CRI) for better light quality, and reducing cost per lumen. Packaging trends include miniaturization, improved thermal management designs, and higher maximum drive currents for greater output from a small footprint. There is also a growing emphasis on smart lighting and tunable white systems, where LEDs of different color temperatures can be mixed.