7070 White LED Datasheet - Size 7.0x7.0x2.8mm - Voltage 26-30V - Power 10.5W - English Technical Document

1. Product Overview

This document details the specifications for the T7C series of high-power white light-emitting diodes (LEDs). The series is designed around a 7070 package format, indicating a physical size of 7.0mm x 7.0mm. These LEDs are engineered for applications requiring high luminous output and robust thermal performance. The core design philosophy emphasizes a balance between high current capability and efficient heat dissipation, making them suitable for demanding lighting environments.

The primary positioning of this product line is within the general and architectural lighting markets. Its key advantages include a compact footprint relative to its power handling, a wide viewing angle for broad illumination, and compliance with modern manufacturing and environmental standards such as lead-free reflow soldering and RoHS directives. The target applications are diverse, ranging from indoor and outdoor signage backlighting to architectural accent lighting and general illumination retrofits, where reliability and consistent light output are critical.

2. Technical Parameter Analysis

2.1 Electro-Optical Characteristics

The fundamental performance of the LED is defined at a standard test condition of a forward current (IF) of 300mA and a junction temperature (Tj) of 25°C. The luminous flux output is directly correlated with the Correlated Color Temperature (CCT) and Color Rendering Index (CRI). For instance, a 4000K LED with a CRI of 70 (Ra70) has a typical luminous flux of 1410 lumens, with a minimum guaranteed value of 1300 lumens. As the CRI increases to 90 (Ra90), the typical output decreases to 1170 lumens, with a 1000-lumen minimum, illustrating the typical trade-off between color quality and light output efficiency. All luminous flux measurements have a stated tolerance of ±7%, and CRI measurements have a tolerance of ±2.

2.2 Electrical and Thermal Ratings

The absolute maximum ratings establish the operational boundaries for safe and reliable use. The maximum continuous forward current (IF) is 350 mA, with a higher pulsed current (IFP) of 480 mA allowed under specific conditions (pulse width ≤100μs, duty cycle ≤1/10). The maximum power dissipation (PD) is 10.5 Watts. The device can withstand a reverse voltage (VR) of up to 5V. The operating temperature range (Topr) is specified from -40°C to +105°C, while the storage temperature (Tstg) ranges from -40°C to +85°C. The maximum allowable junction temperature (Tj) is 120°C. The soldering temperature profile is critical for assembly, with a peak of 230°C or 260°C sustained for a maximum of 10 seconds during reflow.

Under standard electrical conditions (IF=300mA), the forward voltage (VF) typically falls between 26V and 30V, with a tolerance of ±3%. The thermal resistance from the junction to the solder point (Rth j-sp) is a key parameter for thermal management design, with a typical value of 1.5 °C/W. This low value is indicative of the thermally enhanced package design, facilitating heat transfer away from the LED chip. The viewing angle (2θ1/2), defined as the angle where intensity is half the peak value, is 120 degrees, providing a wide beam pattern.

3. Binning System Explanation

3.1 Luminous Flux and CCT/CRI Binning

The product is sorted into performance bins to ensure consistency for the end-user. The binning structure is multi-dimensional, covering luminous flux, forward voltage, and chromaticity. For luminous flux, bins are defined by a letter code (e.g., 3C, 3D, 3E) with specific minimum and maximum lumen ranges. These ranges vary depending on the CCT and CRI combination. For example, a 3000K, Ra80 LED has bins ranging from 3B (1100-1200 lm) to 3E (1400-1500 lm). This allows designers to select LEDs with tightly controlled brightness for uniform lighting applications.

3.2 Forward Voltage and Chromaticity Binning

Forward voltage is binned into two codes: 6F (26-28V) and 6G (28-30V). Selecting LEDs from the same voltage bin can simplify driver design and improve system efficiency. Chromaticity is controlled within a 5-step MacAdam ellipse for each CCT, ensuring minimal perceptible color difference between LEDs. The center coordinates (x, y) and ellipse parameters (a, b, Φ) are provided for standard CCTs like 2700K, 4000K, and 6500K. The document notes that Energy Star binning standards are applied to all products within the 2600K to 7000K range, which is a common requirement for commercial lighting projects.

4. Performance Curve Analysis

The datasheet includes several graphical representations of performance. The relationship between forward current and relative luminous flux shows how light output increases with current, but also implies the need for thermal management at higher currents. The spectrum graphs for different CRI levels (Ra70, Ra80, Ra90) visually demonstrate the fuller, more continuous spectrum associated with higher CRI values, which is crucial for accurate color rendering. The viewing angle distribution plot confirms the Lambertian-like emission pattern with a 120-degree half-angle.

Thermal characteristics are further detailed in curves showing relative luminous flux and forward voltage as functions of solder point temperature (Ts). These curves are essential for predicting performance in real-world conditions where the LED operates above 25°C. The graph of maximum allowable forward current versus ambient temperature provides a derating guideline to prevent overheating. Additionally, a plot shows the shift in CIE chromaticity coordinates with increasing ambient temperature, which is important for applications where color stability is critical.

5. Mechanical and Package Information

The package is a surface-mount device (SMD) with dimensions of 7.00mm (±0.1mm) in length and width, and a height of 2.80mm (±0.1mm). A detailed dimensioned drawing is provided, including key features such as the solder pad layout, which measures 6.10mm x 6.10mm. The chip arrangement within the package is specified as 9 series and 2 parallel connections, which explains the relatively high typical forward voltage of 28V. Clear polarity marking is shown, identifying the cathode and anode pads to prevent incorrect installation. The recommended land pattern for PCB design is also illustrated, showing a 7.50mm x 7.50mm pad with a 6.01mm gap between the anode and cathode sections.

6. Soldering and Assembly Guidelines

The LED is compatible with lead-free reflow soldering processes. The absolute maximum soldering temperature is clearly stated: the device can withstand a peak temperature of 230°C or 260°C for a maximum duration of 10 seconds. It is crucial for assembly technicians to adhere to this profile to prevent damage to the internal silicone lens, phosphor layer, or wire bonds. The storage conditions are also specified, requiring an environment between -40°C and +85°C to maintain long-term reliability before use. Care must be taken during handling to avoid electrostatic discharge (ESD), as the device has an ESD withstand rating of 1000V (Human Body Model).

7. Packaging and Ordering Information

The part numbering system is alphanumeric and detailed in a table. The code structure allows for the specification of multiple parameters. The first position (X1) indicates the package type, where \"7C\" corresponds to the 7070 package. The second position (X2) defines the CCT or color (e.g., 27 for 2700K, 40 for 4000K, BL for Blue). The third position (X3) indicates the Color Rendering Index (7 for Ra70, 8 for Ra80, 9 for Ra90). Subsequent positions specify the number of serial and parallel chips, component codes, and internal classifications. A typical part number following this convention would be T7C***92R-*****, where the specific digits and letters define its exact performance bin and characteristics.

8. Application Recommendations

8.1 Typical Application Scenarios

Due to its high luminous flux and power capability, this LED series is well-suited for several applications. In architectural and decorative lighting, it can be used for wall washing, cove lighting, or highlighting structural features. For retrofit projects, it can replace traditional high-wattage light sources in downlights or panel lights, offering energy savings and longer life. Its output makes it effective for general lighting in commercial or industrial settings. The wide viewing angle is particularly beneficial for backlighting indoor and outdoor sign boards, ensuring even illumination across the sign area.

8.2 Design Considerations

Successful implementation requires careful design. Thermal management is paramount; the low thermal resistance of 1.5 °C/W is only effective if the LED is mounted on a properly designed Metal Core PCB (MCPCB) with adequate heat sinking. The driver must be capable of providing a constant current up to 350mA and handling the high forward voltage (up to 30V). Designers should refer to the derating curve for maximum forward current to ensure reliability at elevated ambient temperatures. For color-critical applications, specifying a tight chromaticity bin (5-step MacAdam) and understanding the color shift with temperature (as shown in Fig. 9) is necessary.

9. Technical Comparison and Differentiation

Compared to smaller package LEDs (e.g., 3030, 5050), the 7070 package offers significantly higher maximum power dissipation (10.5W) and luminous flux output, making it a choice for higher-intensity applications without needing to densely populate a board with many lower-power LEDs. The thermally enhanced package design, evidenced by the low Rth j-sp, is a key differentiator that supports sustained high-current operation. The integrated series-parallel chip configuration (9S2P) results in a higher operating voltage, which can be an advantage in certain driver topologies by reducing current requirements for the same power level.

10. Frequently Asked Questions (FAQ)

Q: What is the difference between the \"Typ\" and \"Min\" values for luminous flux?
A: The \"Typ\" (Typical) value represents the average output from production. The \"Min\" (Minimum) value is the guaranteed lower limit; any LED shipped in that bin will meet or exceed this value. Designers should use the \"Min\" value for conservative system design.

Q: Can I drive this LED at 350mA continuously?
A: While 350mA is the absolute maximum rating, continuous operation at this current requires excellent thermal management to keep the junction temperature well below 120°C. Referencing the derating curve (Fig. 10) is essential. Operating at or below the test current of 300mA is recommended for optimal lifetime and reliability.

Q: How do I interpret the CIE chromaticity diagram and 5-step ellipse?
A: The CIE diagram plots color in a 2D space. The ellipse defines the area within which the LED's color coordinates will fall. A 5-step MacAdam ellipse is a standard measure of color consistency; LEDs within the same ellipse will appear nearly identical in color to the human eye under typical viewing conditions.

11. Practical Application Case Study

Consider designing a high-bay LED fixture for an industrial warehouse. The goal is to replace 400W metal halide fixtures. A design using multiple 7070 LEDs could be developed. The designer would select a 5000K, Ra80 bin (e.g., 3E for 1300-1400 lm) for a balance of efficiency and color quality. The LEDs would be mounted on a large aluminum MCPCB acting as a heat spreader, which is then attached to the fixture's aluminum housing. A constant current driver rated for the total voltage (number of LEDs in series * VF) and current (~300mA per string) would be used. The wide 120-degree beam angle would help reduce the number of fixtures needed by providing broad coverage from each point. The design would be validated by thermal testing to ensure junction temperatures remain within safe limits under the warehouse's maximum ambient temperature.

12. Technical Principle Introduction

A white LED typically uses a blue-emitting indium gallium nitride (InGaN) semiconductor chip. Part of the blue light is converted to longer wavelengths (yellow, red) by a phosphor layer coating the chip. The mixture of unconverted blue light and the phosphor-emitted light results in the perception of white light. The Correlated Color Temperature (CCT) is controlled by the phosphor composition, shifting the white point from warm (2700K, more red/yellow) to cool (6500K, more blue). The Color Rendering Index (CRI) measures how accurately the LED renders colors compared to a reference light source; a higher CRI requires a phosphor blend that emits a more continuous spectrum across the visible range, which often absorbs more of the initial blue light, reducing overall efficiency (lumens per watt).

13. Industry Trends and Developments

The high-power LED market continues to evolve towards higher efficacy (more lumens per watt), improved color quality (higher CRI with less efficacy penalty), and greater reliability. There is a trend for packages like the 7070 to offer increased maximum drive currents and power dissipation as chip technology improves. Another significant trend is the standardization of color and flux binning to simplify supply chains for large lighting manufacturers. Furthermore, there is growing integration of secondary optics and even driver components within the LED package to reduce system complexity. The emphasis on thermal performance, as seen in this datasheet's low Rth j-sp specification, remains a critical focus area, enabling smaller, more powerful, and longer-lasting lighting solutions.