LTW-020ZDCG White LED Datasheet - SMD Package - Typical Voltage 3.2V - 20mA - Luminous Intensity 1000-1720mcd - Technical Documentation

1. Product Overview

This component is a white surface-mount light-emitting diode, designed as a compact, energy-efficient light source. It combines the inherent long lifespan and high reliability of LED technology with competitive brightness levels, aiming to provide design flexibility for solid-state lighting applications intended to replace traditional lighting solutions.

1.1 Core Advantages and Target Market

Key features of this LED include compatibility with automatic placement equipment, suitability for infrared and vapor phase reflow soldering processes, and compliance with green product standards (lead-free and RoHS compliant). It is packaged in 12mm tape and reel, wound on a 7-inch diameter reel.

Main application areas:

• Reading lights inside cars, buses, and airplanes.
• Portable lighting, such as flashlights and bicycle lights.
• Architectural and decorative lighting: downlights, cove lighting, under-cabinet lighting, task lighting.
• Outdoor and Security Lighting: Bollard Lights, Garden Lights.
• Signage: Edge-Lit Signs for Exit or Point-of-Sale Display.
• Signal Lighting: Traffic signals, beacons, railway crossing lights.

2. Technical Parameters: An In-Depth and Objective Interpretation

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation under reverse bias conditions is specifically warned against.

• Power Dissipation:120 mW
• Peak Forward Current:100 mA (at 1/10 duty cycle, 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 conditions:Peak temperature 260°C, maximum 10 seconds (lead-free process).

2.2 Electro-Optical Characteristics

Measurement conditions are ambient temperature (Ta) 25°C, forward current (IF) 20 mA, unless otherwise specified.

• Luminous Intensity (IV):Minimum 1000 mcd, typical 1720 mcd. This parameter is measured using a sensor with a filter matched to the CIE photopic human eye response curve.
• Viewing angle (2θ1/2):110 degrees. This angle defines the angular distribution range where the luminous intensity is at least half of the peak intensity.
• Chromaticity coordinates (x, y):Based on the CIE 1931 chromaticity diagram. The typical values provided are x=0.300, y=0.290. The tolerance for these coordinates is ±0.01. The referenced test standard is CAS140B.
• Forward voltage (VF):At IF=20mA, minimum 2.9 V, maximum 3.6 V.
• ESD Tolerance Voltage:2 kV (Human Body Model). It is strongly recommended to implement appropriate ESD protection measures, including the use of grounded wrist straps and equipment.

3. Explanation of the Binning System

Products are classified into different bins based on key parameters to ensure consistency within production batches. Designers must consider these bins to achieve color and brightness matching in their applications.

3.1 Forward Voltage (VF) Binning

LEDs are binned (V0 to V6) based on their forward voltage drop at 20mA. The voltage range for each bin is 0.1V, with an additional ±0.1V tolerance per bin.

• Misali: Matakin V0 ya rufe daga 2.9V zuwa 3.0V.

3.2 Luminous Intensity (IV) Binning

LEDs are binned (T, A, B, C, D) according to their luminous intensity at 20mA. Each bin has a tolerance range of ±10%.

• Example: Bin D covers 1580 mcd to 1720 mcd.

3.3 Chromaticity Zone Grade (Chromaticity Binning)

Detailed tables define specific color zone grades (e.g., A52, A53, BE1, BG3). Each grade is defined by a quadrilateral or triangular area on the CIE 1931 chromaticity diagram, specified by three or four (x, y) coordinate points. This allows for precise color selection and matching for applications requiring specific white point coordinates.

4. Performance Curve Analysis

The datasheet references typical electrical and optical characteristic curves measured at an ambient temperature of 25°C. While the provided text does not detail specific charts, such curves typically include:

• Relative luminous intensity vs. forward current:Shows how the light output increases with current, typically in a non-linear manner, eventually reaching saturation.
• Forward Voltage vs. Forward Current:IV curve, showing the exponential relationship characteristic of a diode.
• Relative Luminous Intensity vs. Ambient Temperature:It is explained that as the junction temperature increases, the light output will decrease, which is a key factor in thermal management.
• Spectral Power Distribution:For white LEDs (which may be blue chips with phosphors), this will show the blue peak and the broader phosphor-converted yellow spectrum.

5. Mechanical and Packaging Information

5.1 Outline Dimensions

All dimensions are in millimeters, with a standard tolerance of ±0.1 mm unless otherwise specified. The package is in the industry-standard SMD format. The anode pin is clearly marked in the diagram to facilitate correct identification of polarity during assembly.

5.2 Recommended PCB Pad Layout

Provides printed circuit board pad pattern design to ensure reliable soldering during infrared or vapor phase reflow processes. Following this recommended pad layout is crucial for forming good solder joints and ensuring mechanical stability.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Parameters

This component is rated for lead-free reflow soldering with a peak temperature of 260°C for up to 10 seconds. It is recommended to use a reflow profile compliant with the J-STD-020D standard. This profile should include appropriate preheating, soaking, reflow, and cooling stages to minimize thermal shock and ensure reliable solder joints.

6.2 Storage and Operating Conditions

According to JEDEC J-STD-020, the Moisture Sensitivity Level (MSL) for this LED is Level 3.

• Sealed packaging:Store at ≤30°C and ≤90% RH. Shelf life is one year in a moisture barrier bag with desiccant.
• Opened packaging:Store at ≤30°C and ≤60% RH. Components must be soldered within 168 hours (7 days) after opening. If the humidity indicator card turns pink (≥10% RH) or the exposure time is exceeded, it is recommended to bake at 60°C for at least 48 hours before use. Reseal unused parts with desiccant.

6.3 Cleaning

If cleaning is required after soldering, only the specified solvents may be used. It is acceptable to immerse the LED in ethanol or isopropanol at room temperature for no more than one minute. The use of unspecified chemical cleaners is prohibited as they may damage the LED package or optical components.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

Components are packaged in embossed carrier tape with a width of 12mm, wound on reels with a diameter of 7 inches (178mm).

• Reel Capacity:Up to 2000 pieces per reel.
• Cover Tape:Holes are sealed with top cover tape.
• Missing components:According to the specification, a maximum of two consecutive missing components ("lamps") is allowed.
• Standard:Packaging complies with EIA-481-1-B specification.

The specification provides detailed dimensional drawings of the carrier tape pockets and reels.

8. Application Suggestions and Design Considerations

8.1 Design Considerations

• Rate Limiting:Always drive the LED using a constant current source or current limiting resistor. The absolute maximum DC current is 30mA; the typical operating current is 20mA.
• Thermal Management:Despite the low power dissipation (max 120mW), ensuring sufficient PCB copper area or thermal vias helps maintain a lower junction temperature, thereby preserving light output and lifespan.
• ESD Protection:Implement ESD protection measures in circuits and during operation, as the device's rated ESD withstand voltage is only 2kV HBM.
• Optics:A 110-degree viewing angle is suitable for wide-area illumination. For focused beams, secondary optical elements (lenses) are required.

8.2 Application Limitations and Precautions

The datasheet contains important warnings regarding the scope of application. These LEDs are suitable for standard commercial and industrial electronic products. They are not designed or certified for use in situations where failure could directly endanger life or health, such as:

• Aviation control systems
• Medical Life Support Equipment
• Traffic Safety Critical Signals (Without Additional Certification)
• Other high-reliability/safety-critical systems

For such applications, consult the manufacturer.

9. Technical Comparison and Differentiation

Although this single specification sheet does not provide a direct comparison with other models, the key differentiating characteristics of this component can be inferred:

• Brightness Range:Provides relatively high luminous intensity (up to 1720 mcd at 20mA) within its compact package size, targeting applications requiring good point source brightness.
• Color Binning:The extensive color binning grade table allows for precise color selection, which is highly beneficial for applications requiring a consistent white appearance across multiple LEDs.
• Compatibility:Fully compatible with standard SMD assembly processes (automatic placement, infrared/vapor phase reflow soldering), making it a plug-and-play solution for high-volume manufacturing.

10. Frequently Asked Questions Based on Technical Parameters

10.1 What are the typical operating current and voltage?

The standard test condition and typical operating point is a forward current of 20mA. At this current, the forward voltage typically ranges from 2.9V to 3.6V, depending on the VF bin. The power dissipation is approximately 60-70mW.

10.2 Yaya ake fassara lambobin rarrabuwar launi?

Alphanumeric codes (e.g., A52, BE3) correspond to specific areas on the CIE 1931 chromaticity diagram as defined in the color bin classification table. To ensure color consistency in the design, specify and use LEDs from the same color bin grade. The first letter/number is typically used to group similar correlated color temperatures or hues.

10.3 Zan iya amfani da wutar lantarki na 5V don kunna wannan LED?

It cannot be driven directly. Connecting a 5V power supply directly across the LED will cause excessive current, likely exceeding the Absolute Maximum Ratings and damaging the device. You must use a series current-limiting resistor or a constant current driver. For example, with a 5V supply, a target current of 20mA, and assuming a VF of 3.2V, the required series resistor is R = (5V - 3.2V) / 0.02A = 90 ohms (a standard 91-ohm resistor can be used).

10.4 Menene buƙatun aiki na matakin MSL 3?

MSL 3 yana nufin cewa bayan buɗe jakar kariya daga ɗanɗano, fakitin zai iya jure har zuwa sa'o'i 168 (kwanaki 7) na yanayin ɗakin aikin masana'anta (≤30°C/60% RH). Idan an buɗe jakar, kuna da mako guda don kammala aikin sake zubarwa. Idan ya wuce wannan lokacin, dole ne a gasa sassan a 60°C na sa'o'i 48, don cire ɗanɗano da aka sha, don hana "fashewar gasa" (fashewar fakitin) yayin aikin sake zubarwa.

11. Misalin ƙira da amfani na ainihi.

11.1 Example: Designing a PCB-Mounted Indicator Light

Scenario:Create a simple status indicator light powered by a 3.3V microcontroller GPIO pin.
Design Steps:

1. Rate Limiting:The GPIO pin can provide 20mA current. This matches the typical current of an LED. No external driver is needed.
2. Resistance calculation (for safety):Even though VCC (3.3V) is close to VF (~3.2V), it is good practice to add a small series resistor to limit inrush current. R = (3.3V - 3.2V) / 0.02A = 5 ohms. Use a 10-ohm resistor for safer current limiting.
3. PCB layout:Use the recommended pad layout. Connect the cathode (marked in the outline drawing) to the resistor, then to the GPIO pin. Connect the anode to the 3.3V power rail. Include a small copper pour under the LED pad to assist with slight heat dissipation.
4. Software:Set the GPIO pin high to turn on the LED.

11.2 Misal: Tsarin LED masu yawa don hasken aiki

Scenario:Design an under-cabinet lighting fixture using 10 LEDs to achieve uniform illumination.
Design Considerations:

• Color Matching:Specify a single, strict color bin (e.g., BE2) to the supplier to avoid visible color differences between LEDs.
• Driving Method:Use a constant-current LED driver IC capable of providing 200mA (10 LEDs * 20mA) for series or series-parallel configurations. Due to voltage drop, a simple linear regulator would be very inefficient.
• Thermal Management:Space LEDs appropriately on the Metal Core PCB (MCPCB) to facilitate heat dissipation. Each LED at 120mW implies a total power consumption of 1.2W, necessitating deliberate thermal design.
• Optics:The inherent 110-degree beam angle may be sufficient. To achieve a more focused or diffused effect, consider adding a light guide plate or a diffuser.

12. Gabatarwar Ɗan Taƙaitaccen Bayani Akan Aiki

White LEDs like the LTW-020ZDCG typically operate based on the phosphor conversion principle. The core of the device is a semiconductor chip, usually made of Indium Gallium Nitride (InGaN), which emits blue light when forward-biased (current passes through). This blue-emitting chip is coated or covered with a phosphor material—commonly based on Cerium-doped Yttrium Aluminum Garnet (YAG).

When blue photons from the chip strike the phosphor, a portion of them are absorbed. The phosphor then re-emits this energy in a broader spectrum, primarily in the yellow region. The remaining unabsorbed blue light mixes with the yellow light emitted by the phosphor, creating the perception of white light in the human eye. The precise ratio of blue to yellow light, along with the specific phosphor composition, determines the correlated color temperature (CCT) and chromaticity coordinates (x, y) of the resulting white light, thereby forming the detailed binning system described in the datasheet.

13. Technology Trends and Development

The field of Solid State Lighting (SSL) continues to evolve. Observable general trends within the industry provide context for understanding such components, including:

• Efficiency improvement (lumens per watt):Continuous improvements in semiconductor epitaxy, chip design, and phosphor technology have steadily increased the luminous efficacy of white LEDs, reducing energy consumption for the same light output.
• Color Quality Improvement:The development of multi-phosphor mixtures and new phosphor materials (e.g., quantum dots) aims to improve the Color Rendering Index (CRI), making colors appear more natural under LED lighting and providing a wider range of precise color temperatures.
• Miniaturization and Higher Density:Advances in packaging technology enable LEDs to occupy a smaller footprint and achieve higher power density, leading to more compact and brighter lighting solutions.
• Smart and Connected Lighting:Integrating control electronics directly into the LED package or module for dimming, color tuning, and connectivity (IoT) is a growing trend, moving beyond simple passive components.
• Reliability and Lifetime Prediction:A deeper understanding of failure mechanisms and improved testing methods have made life predictions (L70, L90 metrics) under various operating conditions more accurate, which is crucial for professional lighting design.

The components described in this specification represent a mature point in this technological development process, providing a reliable, standardized solution for a wide range of general lighting applications.