T20 Series White LED Specification - 2016 Package - 2.0x1.6x1.75mm - 11V Typ - 0.33W - English Technical Document

1. Product Overview

The T20 series represents a compact, high-performance white LED solution designed for modern lighting applications. This top-view LED, designated with the 2016 package size, is engineered to deliver reliable and efficient illumination. Its core advantages stem from a thermally enhanced package design, which facilitates better heat dissipation, allowing for higher current operation and sustained luminous output. The device is characterized by a wide viewing angle, making it suitable for applications requiring broad light distribution. It is fully compliant with Pb-free reflow soldering processes and adheres to RoHS environmental standards, ensuring compatibility with contemporary manufacturing requirements and global regulations.

The target market for this LED is diverse, encompassing both commercial and residential lighting sectors. Its primary applications include interior lighting fixtures, retrofit solutions for replacing traditional light sources, general ambient lighting, and architectural or decorative lighting where both performance and form factor are critical.

2. Technical Parameter Deep Dive

2.1 Electro-Optical Characteristics

The fundamental performance of the LED is defined at a standard test condition of a forward current (IF) of 30mA and a junction temperature (Tj) of 25°C. The luminous flux output varies with the Correlated Color Temperature (CCT). For instance, a 2700K (warm white) LED offers a typical luminous flux of 34.5 lumens with a minimum of 32 lumens, while cooler CCTs like 4000K, 5000K, 5700K, and 6500K provide a higher typical output of 36.5 lumens (minimum 34 lumens). All variants maintain a high Color Rendering Index (CRI) of Ra80, ensuring good color fidelity. The tolerance for luminous flux measurement is ±7%, and the CRI tolerance is ±2.

The device features a very wide viewing angle (2θ1/2) of 120 degrees, providing a broad and uniform light emission pattern ideal for area lighting.

2.2 Electrical Parameters

The forward voltage (VF) at 30mA is typically 11V, with a range from 9.5V to 12V, and a measurement tolerance of ±0.3V. The absolute maximum ratings define the operational limits: a continuous forward current (IF) of 40mA, a pulsed forward current (IFP) of 60mA (under specific pulse conditions), and a maximum power dissipation (PD) of 440mW. The reverse voltage (VR) is limited to 5V. Care must be taken not to exceed these ratings to ensure long-term reliability.

2.3 Thermal Characteristics

Thermal management is crucial for LED performance and lifespan. The thermal resistance from the junction to the solder point (Rth j-sp) is specified as 40°C/W under standard test conditions. The absolute maximum junction temperature (Tj) is 120°C. The device is rated for an operating temperature range (Topr) of -40°C to +105°C. The derating curve (Fig. 8) clearly illustrates how the allowable forward current must be reduced as the ambient temperature increases to prevent overheating and premature failure.

3. Binning System Explanation

3.1 Luminous Flux Binning

The LEDs are sorted into luminous flux bins to ensure consistency. For example, a 4000K LED with Ra80 can be found in bins E1 (34-36 lm), E2 (36-38 lm), and E3 (38-42 lm). The bin code (e.g., D9, E1, E2) is part of the part numbering system and allows designers to select LEDs with precise output levels for their application.

3.2 Forward Voltage Binning

Similarly, forward voltage is binned to aid in circuit design, particularly for driving multiple LEDs in series. Available bins include 1C (8-9V), 1D (9-10V), and 5X (10-12V). Selecting LEDs from the same voltage bin can help achieve more uniform current distribution.

3.3 Chromaticity Binning

The color consistency is tightly controlled using the CIE 1931 chromaticity diagram. Each CCT (e.g., 2700K, 3000K) is defined by a target center coordinate (x, y) and a tolerance ellipse. The specification states that the color ranks fall within a 5-step MacAdam ellipse, which is a standard for defining perceptible color differences. Energy Star binning standards are applied across the 2600K to 7000K range, ensuring the LEDs meet stringent color uniformity requirements for quality lighting products.

4. Performance Curve Analysis

The datasheet provides several key graphs for understanding performance under varying conditions.

Relative Intensity vs. Forward Current (Fig. 3): This curve shows how light output increases with current. It is typically non-linear, and operating beyond the recommended current can lead to efficiency droop and accelerated degradation.

Forward Voltage vs. Forward Current (Fig. 4): This IV characteristic curve is essential for designing the driver circuit. It shows the relationship between the voltage across the LED and the current flowing through it.

Relative Luminous Flux vs. Ambient Temperature (Fig. 5): This graph demonstrates the negative impact of rising temperature on light output. As the ambient (and consequently junction) temperature increases, the luminous flux decreases. This underscores the importance of effective thermal design.

Relative Forward Voltage vs. Ambient Temperature (Fig. 6): The forward voltage has a negative temperature coefficient, meaning it decreases slightly as temperature rises. This can be a factor in constant-current driver design.

Chromaticity Shift vs. Ambient Temperature (Fig. 7): This plot is critical for color-sensitive applications. It shows how the x and y color coordinates drift with changes in temperature, which is vital information for maintaining color consistency in varying environments.

Color Spectrum (Fig. 1): This graph displays the spectral power distribution of the emitted white light, which is a combination of the blue LED chip and the phosphor coating. It helps in understanding the color quality and potential applications.

5. Mechanical and Package Information

The LED utilizes the 2016 package footprint, with dimensions of 2.0mm in length, 1.6mm in width, and a height of 1.75mm. The package drawing provides a bottom view illustrating the soldering pad pattern. Clear polarity identification is shown: the cathode is marked. The dimensional tolerance, unless otherwise specified, is ±0.1mm. This compact size allows for high-density PCB layouts, making it suitable for slim lighting fixtures.

6. Soldering and Assembly Guidelines

The device is designed for reflow soldering processes. A detailed reflow profile is provided with specific parameters: The ramp-up rate from liquidus temperature (TL=217°C) to peak temperature (Tp=260°C max) should not exceed 3°C/second. The time maintained above TL (tL) should be between 60 and 150 seconds. The peak package body temperature must not exceed 260°C, and the time within 5°C of this peak (tp) should be a maximum of 30 seconds. The ramp-down rate should be a maximum of 6°C/second. The total time from 25°C to peak temperature should not exceed 8 minutes. Adhering to this profile is critical to prevent thermal damage to the LED package, solder joints, and internal die attach materials.

7. Packaging and Ordering Information

The part numbering system is comprehensive, allowing for precise specification. The model is T20**811A-*****. The numbering system breaks down as follows: X1 indicates the type code (20 for 2016 package). X2 is the CCT code (e.g., 27 for 2700K). X3 is the color rendering index (8 for Ra80). X4 and X5 indicate the number of serial and parallel chips, respectively. X6 is a component code. X7 is a color code defining specific performance grades (e.g., M for ANSI standard). X8, X9, and X10 are for internal and spare codes. This system enables users to order the exact LED variant required for their design.

8. Application Suggestions

8.1 Typical Application Scenarios

As listed, the primary applications are interior lighting, retrofits, general lighting, and architectural/decorative lighting. Its high flux output and wide angle make it excellent for downlights, panel lights, tube lights, and decorative strips. The 120-degree beam angle is particularly beneficial for fixtures requiring wide illumination coverage without hotspots.

8.2 Design Considerations

Thermal Management: Given the thermal resistance of 40°C/W, proper heat sinking is mandatory, especially when operating at or near the maximum current. The PCB should be designed with adequate thermal vias and possibly connected to a metal core or heatsink to maintain a low junction temperature.

Electrical Driving: A constant current driver is recommended to ensure stable light output and color over the LED's lifetime. The driver should be selected based on the forward voltage bin and the required operating current, ensuring it does not exceed the absolute maximum ratings. The derating curve must be consulted for high-temperature environments.

Optical Design: The top-view nature and wide beam angle may require secondary optics (lenses or diffusers) if a specific beam pattern or glare control is needed.

9. Technical Comparison and Differentiation

Compared to standard mid-power LEDs, the T20/2016 package offers a balance between compact size and good thermal performance due to its thermally enhanced design. Its typical forward voltage of 11V at 30mA suggests it may contain multiple chip configurations internally. The wide 120-degree viewing angle is a key differentiator from LEDs with narrower beams, making it more suitable for general lighting rather than spotlighting. The adherence to 5-step MacAdam ellipses and Energy Star binning places it in a category focused on high color consistency, which is a significant advantage over LEDs with looser color tolerances.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: What is the actual power consumption of this LED?
A: At the typical operating condition of 30mA and 11V, the power consumption is 0.33W (30mA * 11V = 330mW). This is below the maximum power dissipation rating of 440mW.

Q: Can I drive this LED with a 12V supply?
A: Not directly. The LED requires a constant current driver, not a constant voltage supply. Connecting it directly to a 12V source would likely cause excessive current flow, exceeding the absolute maximum rating and destroying the LED. A driver circuit that regulates current to 30mA (or another desired level within spec) must be used.

Q: How does temperature affect the light output?
A: As shown in Fig. 5, light output decreases as ambient temperature rises. Effective heat sinking is crucial to maintain high luminous flux and long life.

Q: What does "5-step MacAdam ellipse" mean for my application?
A: It means the LEDs are binned so tightly that the color difference between any two LEDs in the same bin is virtually imperceptible to the human eye under standard viewing conditions. This is essential for applications where color uniformity across multiple LEDs is critical, such as in panel lights or linear fixtures.

11. Practical Design and Usage Case

Consider designing a retrofit LED tube light to replace a traditional fluorescent T8 tube. A typical design might use 120 pieces of this T20 LED arranged linearly on a metal-core PCB (MCPCB). Given its wide 120-degree viewing angle, the light distribution would be excellent for general office illumination. The designer would select LEDs from the same luminous flux and voltage bin (e.g., E2 and 5X) to ensure uniform brightness and current sharing. The MCPCB would be attached to an aluminum housing acting as a heatsink. A constant current driver would be designed to provide approximately 30mA per LED string, accounting for the total forward voltage of the series-connected LEDs. The reflow soldering profile would be strictly followed during assembly. This setup would leverage the LED's high efficiency, long life, and good color rendering to create an energy-saving, high-quality lighting product.

12. Operating Principle Introduction

A white LED operates on the principle of electroluminescence in a semiconductor material, combined with phosphor conversion. The core is a semiconductor chip, typically made of indium gallium nitride (InGaN), which emits blue light when a forward current is applied. This blue light then strikes a layer of phosphor coating (often based on yttrium aluminum garnet or YAG) deposited on or around the chip. The phosphor absorbs a portion of the blue light and re-emits it as yellow light. The combination of the remaining blue light and the emitted yellow light is perceived by the human eye as white light. The exact shade of white (CCT) is controlled by the composition and thickness of the phosphor layer. The wide viewing angle is achieved through the package design and the diffusion of light through the encapsulating lens.

13. Technology Trends and Development

The lighting industry continues to push for higher efficacy (lumens per watt), improved color quality (higher CRI and R9 values), and better reliability. Trends include the development of novel phosphor materials for more saturated red emission (improving CRI R9), the use of remote phosphor designs for better color uniformity and thermal management, and the integration of chip-scale package (CSP) technologies for even smaller form factors. Furthermore, there is a growing focus on smart lighting, requiring LEDs that can be reliably dimmed and controlled via protocols like DALI or Zigbee. The T20 series, with its thermally enhanced package and consistent binning, aligns with the industry's demand for reliable, high-quality components that form the foundation of both basic and advanced lighting systems. The move towards human-centric lighting (HCL), which tunes light color and intensity to support circadian rhythms, also relies on the stable and predictable performance of LEDs like those in this series.