Table of Contents
- 1. Product Overview
- 2. Technical Parameters: In-Depth Objective Interpretation
- 2.1 Absolute Maximum Ratings
- 2.2 Electro-Optical Characteristics
- 3. Binning System Explanation
- 3.1 Luminous Intensity Binning
- 3.2 Forward Voltage Binning
- 3.3 Color Binning
- 4. Performance Curve Analysis
- 5. Mechanical and Package Information
- 5.1 Package Dimensions
- 5.2 Polarity Identification and Mounting
- 6. Soldering and Assembly Guidelines
- 6.1 Lead Forming
- 6.2 Soldering Conditions
- 6.3 Storage Conditions
- 7. Packaging and Ordering Information
- 7.1 Packing Specification
- 7.2 Label Explanation
- 7.3 Model Number Designation
- 8. Application Suggestions
- 8.1 Typical Application Scenarios
- 8.2 Design Considerations
- 9. Technical Comparison and Differentiation
- 10. Frequently Asked Questions (Based on Technical Parameters)
- 10.1 What is the difference between Continuous and Peak Forward Current?
- 10.2 How do I choose the right current-limiting resistor?
- 10.3 Can I use this LED outdoors?
- 11. Practical Use Case Example
- 12. Operating Principle Introduction
- 13. Technology Trends
- LED Specification Terminology
- Photoelectric Performance
- Electrical Parameters
- Thermal Management & Reliability
- Packaging & Materials
- Quality Control & Binning
- Testing & Certification
1. Product Overview
This document details the specifications for a high-luminosity white light-emitting diode (LED) designed for indicator and backlighting applications. The device utilizes an InGaN semiconductor chip combined with a phosphor-filled reflector to produce white light from blue emission. The LED is housed in a popular T-1 3/4 round package, offering a balance of size and light output suitable for various electronic assemblies.
The core advantage of this product is its high luminous intensity, with typical values reaching significant levels at a standard drive current. It is designed for applications requiring bright, clear visual indicators. The device is compliant with relevant environmental regulations and features built-in electrostatic discharge (ESD) protection, enhancing its reliability in handling and operation.
2. Technical Parameters: In-Depth Objective Interpretation
2.1 Absolute Maximum Ratings
The absolute maximum ratings define the stress limits beyond which permanent damage to the device may occur. These are not for continuous operation.
- Continuous Forward Current (IF): 30 mA. This is the maximum DC current that can be applied continuously to the LED anode.
- Peak Forward Current (IFP): 100 mA. This higher current is permissible only under pulsed conditions, specified at a duty cycle of 1/10 and a frequency of 1 kHz.
- Reverse Voltage (VR): 5 V. Applying a reverse bias voltage exceeding this value can damage the LED's semiconductor junction.
- Power Dissipation (Pd): 110 mW. This is the maximum power the package can dissipate as heat, calculated as the product of forward voltage and current under specified conditions.
- Operating & Storage Temperature: The device is rated for operation from -40°C to +85°C and can be stored from -40°C to +100°C.
- ESD Withstand Voltage (HBM): 4 kV. This indicates the level of electrostatic discharge protection according to the Human Body Model.
- Soldering Temperature: The leads can withstand a peak temperature of 260°C for a maximum of 5 seconds during soldering processes.
2.2 Electro-Optical Characteristics
These parameters are measured at a standard test condition of 25°C ambient temperature and a forward current (IF) of 20 mA, which serves as a common reference point.
- Forward Voltage (VF): Ranges from 2.8 V (Min.) to 3.6 V (Max.), with a typical value implied within this range. This is the voltage drop across the LED when conducting the specified current.
- Luminous Intensity (IV): Has a minimum value of 3600 mcd (millicandela) and can go up to a maximum of 7150 mcd. The actual delivered intensity is subject to a binning system detailed later.
- Viewing Angle (2θ1/2): The typical full viewing angle, at which luminous intensity is half of the peak axial intensity, is 50 degrees. This defines the beam spread of the LED.
- Chromaticity Coordinates: The typical color point in the CIE 1931 color space is x=0.30, y=0.29. This defines the perceived white color of the LED's output.
- Zener & Reverse Characteristics: The device may incorporate a protective Zener diode with a reverse voltage (Vz) of 5.2 V at 5 mA. The reverse leakage current (IR) is up to 50 µA at 5 V.
3. Binning System Explanation
To manage production variations, LEDs are sorted into performance bins. This allows designers to select parts that meet specific minimum requirements for their application.
3.1 Luminous Intensity Binning
LEDs are categorized into three primary bins based on their minimum and maximum luminous intensity measured at IF=20mA. The tolerance for intensity within a bin is ±10%.
- Bin Q: 3600 mcd (Min.) to 4500 mcd (Max.)
- Bin R: 4500 mcd (Min.) to 5650 mcd (Max.)
- Bin S: 5650 mcd (Min.) to 7150 mcd (Max.)
3.2 Forward Voltage Binning
LEDs are also binned according to their forward voltage drop at IF=20mA, with a measurement uncertainty of ±0.1V. This helps in designing consistent current drive circuits, especially when multiple LEDs are connected in series.
- Bin 0: 2.8 V to 3.0 V
- Bin 1: 3.0 V to 3.2 V
- Bin 2: 3.2 V to 3.4 V
- Bin 3: 3.4 V to 3.6 V
3.3 Color Binning
The white color output is controlled within specific regions on the CIE chromaticity diagram. The product combines LEDs from color bins B5 and B6 to form Group 7. The datasheet provides the corner coordinate ranges for these bins (e.g., for B5: x between 0.287-0.311, y between 0.276-0.315), ensuring the white point falls within a defined area. The measurement uncertainty for color coordinates is ±0.01.
4. Performance Curve Analysis
The datasheet includes several characteristic graphs that illustrate device behavior under varying conditions. These are essential for understanding performance beyond the single-point specifications.
- Relative Intensity vs. Wavelength: This spectral distribution curve shows the peak wavelength and the broadened spectrum resulting from the phosphor conversion, typical for white LEDs.
- Directivity Pattern: A polar plot showing the angular distribution of light intensity, correlating with the 50-degree typical viewing angle.
- Forward Current vs. Forward Voltage (I-V Curve): This graph shows the non-linear relationship between current and voltage. The curve's steepness beyond the turn-on voltage highlights the importance of current-controlled driving for stable light output.
- Relative Intensity vs. Forward Current: Demonstrates how light output increases with drive current, typically in a sub-linear manner at higher currents due to efficiency droop and thermal effects.
- Chromaticity Coordinate vs. Forward Current: Shows how the white point (color coordinates) may shift slightly with changes in drive current, which is critical for color-sensitive applications.
- Forward Current vs. Ambient Temperature: Illustrates the derating of the maximum permissible forward current as the ambient temperature increases, a key consideration for thermal management and reliability.
5. Mechanical and Package Information
5.1 Package Dimensions
The LED uses a standard T-1 3/4 (approximately 5mm) round package with a water-clear resin lens. Key dimensional notes include: all dimensions are in millimeters with a general tolerance of ±0.25mm unless specified otherwise; lead spacing is measured at the point where the lead emerges from the package body; and the maximum protrusion of resin below the flange is 1.5mm. The detailed mechanical drawing provides exact values for overall diameter, height, lead diameter, and spacing.
5.2 Polarity Identification and Mounting
The package features a flange with a flat side, which typically indicates the cathode (negative) lead. Proper identification is crucial for correct circuit connection. The leads are designed for through-hole mounting on printed circuit boards (PCBs).
6. Soldering and Assembly Guidelines
Proper handling is critical to prevent damage during assembly.
6.1 Lead Forming
- Bending must occur at least 3mm from the base of the epoxy bulb to avoid stress on the seal.
- Forming should always be done before soldering.
- Excessive stress during forming can crack the epoxy or damage internal bonds.
- Cutting leads should be done at room temperature.
- PCB holes must align precisely with LED leads to avoid mounting stress.
6.2 Soldering Conditions
Recommended parameters are provided to minimize thermal shock:
- Hand Soldering: Iron tip temperature maximum 300°C (for a 30W max iron), soldering time maximum 3 seconds per lead, maintaining a minimum distance of 3mm from the solder joint to the epoxy bulb.
- Wave/Dip Soldering: Preheating to a maximum of 100°C for up to 60 seconds. The solder bath temperature should not exceed 260°C, with the component immersed for a maximum of 5 seconds. The 3mm distance rule also applies.
6.3 Storage Conditions
To prevent moisture absorption, which can cause \"popcorning\" during soldering, LEDs should be stored at or below 30°C and 70% Relative Humidity (RH). The recommended storage life from shipment is 3 months. For longer storage (up to one year), parts should be kept in a sealed, moisture-barrier bag with desiccant, preferably under a nitrogen atmosphere.
7. Packaging and Ordering Information
7.1 Packing Specification
The LEDs are packaged to prevent electrostatic and physical damage. They are first placed in anti-static bags. A quantity of 200 to 500 pieces is packed per bag. Five bags are then placed into an inner carton. Finally, ten inner cartons are packed into a master outside carton for shipment.
7.2 Label Explanation
Packaging labels include several codes: CPN (Customer's Part Number), P/N (Manufacturer's Part Number), QTY (Quantity), CAT (Combination code for Luminous Intensity and Forward Voltage bins), HUE (Color Rank code), REF (Reference), and LOT No. (Traceable production lot number).
7.3 Model Number Designation
The part number 334-15/T1C5-7 QSA follows a specific structure. The suffix codes (represented by squares in the datasheet) allow selection of the specific luminous intensity bin, forward voltage bin, and other optional features as defined in the manufacturer's selection guide.
8. Application Suggestions
8.1 Typical Application Scenarios
As listed in the datasheet, this high-intensity white LED is suitable for:
- Message Panels & Signage: Where bright, individual pixels or indicators are needed.
- Optical Indicators: Status lights on industrial equipment, consumer electronics, or control panels.
- Backlighting: For small LCD displays, membrane switch panels, or decorative lighting where even illumination is required, often used in an array.
- Marker Lights: For equipment, vehicles, or safety applications requiring high visibility.
8.2 Design Considerations
- Current Driving: Always use a series current-limiting resistor or a constant-current driver circuit. Driving the LED directly from a voltage source will likely destroy it due to the exponential I-V relationship.
- Thermal Management: While the power is relatively low, ensuring adequate ventilation or heat sinking is important for maintaining long-term luminous output and reliability, especially at higher ambient temperatures or drive currents.
- Optical Design: The 50-degree viewing angle provides a broad beam. For more focused light, secondary optics like lenses or light pipes may be required.
- Binning Selection: For applications requiring uniform brightness or color across multiple LEDs, specifying a tight intensity bin (e.g., Bin S only) and a specific voltage/color group is advisable.
9. Technical Comparison and Differentiation
Compared to generic 5mm white LEDs, this product offers significantly higher luminous intensity, making it suitable for applications where superior brightness is paramount. The inclusion of a defined binning system for both intensity and forward voltage provides greater predictability and consistency in production runs compared to unbinned or loosely binned alternatives. The built-in ESD protection (4kV HBM) enhances robustness in assembly environments. The specific combination of color bins (B5+B6) targets a particular white point, which may differ from the cooler or warmer white points offered by other products.
10. Frequently Asked Questions (Based on Technical Parameters)
10.1 What is the difference between Continuous and Peak Forward Current?
The Continuous Forward Current (30 mA) is the maximum DC current for safe, long-term operation. The Peak Forward Current (100 mA) is a short-duration, pulsed rating that can be used for brief periods (e.g., in multiplexed displays) but must not be exceeded even momentarily in DC operation, as it will cause overheating and rapid degradation.
10.2 How do I choose the right current-limiting resistor?
Use Ohm's Law: R = (Vsupply - VF) / IF. Use the maximum VF from the datasheet (3.6V) for a conservative design that ensures the current never exceeds 20mA even with part-to-part variation. For example, with a 5V supply: R = (5V - 3.6V) / 0.020A = 70 Ohms. The nearest standard value (68 or 75 Ohms) would be chosen, and its power rating should be checked (P = I2R).
10.3 Can I use this LED outdoors?
The operating temperature range (-40°C to +85°C) allows for use in many outdoor environments. However, the package is not specifically rated for waterproofing or resistance to UV degradation. For direct outdoor exposure, additional environmental protection (conformal coating, sealed enclosures) would be necessary to protect against moisture and sunlight.
11. Practical Use Case Example
Designing a Multi-LED Status Indicator Panel: A control panel requires 20 bright white LEDs to indicate the operational state of various machine functions. Uniform brightness is important for aesthetics and clarity.
- Circuit Design: The designer chooses to drive all LEDs in parallel from a 12V rail. Each LED branch has its own current-limiting resistor. Using the max VF of 3.6V and a target IF of 20mA, the resistor value is (12V - 3.6V)/0.02A = 420 Ohms. A 430 Ohm, 1/4W resistor is selected for each branch.
- Binning Selection: To ensure uniformity, the designer specifies LEDs from Bin S (highest intensity) and requests them from the same production lot and color group (Group 7) to minimize color and brightness variation.
- PCB Layout: Holes are drilled according to the package drawing's lead spacing. A keep-out area of at least 3mm radius around the LED body is maintained to avoid solder wicking during wave soldering.
- Assembly:** The assembler follows the hand-soldering guidelines, using a temperature-controlled iron set to 300°C and completing each joint in under 3 seconds.
12. Operating Principle Introduction
This is a phosphor-converted white LED. The core is a semiconductor chip made of Indium Gallium Nitride (InGaN). When a forward voltage is applied, electrons and holes recombine within the chip's active region, emitting photons. The InGaN material is engineered to emit light in the blue region of the spectrum (typically around 450-455 nm). This blue light is not emitted directly. Instead, it strikes a layer of phosphor material (e.g., Yttrium Aluminum Garnet doped with Cerium, YAG:Ce) that is deposited inside the reflector cup surrounding the chip. The phosphor absorbs a portion of the blue photons and re-emits light across a broader spectrum, predominantly in the yellow range. The mixture of the remaining unabsorbed blue light and the phosphor-generated yellow light is perceived by the human eye as white light. The exact shade (cool white, neutral white, warm white) is determined by the composition and thickness of the phosphor layer.
13. Technology Trends
The technology behind this type of LED continues to evolve. General industry trends include:
- Increased Efficiency (Lumens per Watt): Ongoing improvements in chip epitaxy, light extraction, and phosphor efficiency lead to higher luminous output for the same electrical input, reducing energy consumption.
- Improved Color Rendering: While this datasheet specifies a single white point, newer products often use multi-phosphor blends (e.g., adding red phosphor) to achieve higher Color Rendering Index (CRI) values, making colors appear more natural under the light.
- Miniaturization:** While the T-1 3/4 package remains popular, there is a broad trend towards smaller surface-mount device (SMD) packages (e.g., 3535, 3030, 2835) for higher-density applications, though often at a trade-off with total light output per package compared to larger through-hole types.
- Higher Reliability and Lifetime: Advancements in packaging materials, die attach, and wire bonding continue to push the rated lifetimes (L70/B50) of LEDs further, making them suitable for more demanding applications.
LED Specification Terminology
Complete explanation of LED technical terms
Photoelectric Performance
| Term | Unit/Representation | Simple Explanation | Why Important |
|---|---|---|---|
| Luminous Efficacy | lm/W (lumens per watt) | Light output per watt of electricity, higher means more energy efficient. | Directly determines energy efficiency grade and electricity cost. |
| Luminous Flux | lm (lumens) | Total light emitted by source, commonly called "brightness". | Determines if the light is bright enough. |
| Viewing Angle | ° (degrees), e.g., 120° | Angle where light intensity drops to half, determines beam width. | Affects illumination range and uniformity. |
| CCT (Color Temperature) | K (Kelvin), e.g., 2700K/6500K | Warmth/coolness of light, lower values yellowish/warm, higher whitish/cool. | Determines lighting atmosphere and suitable scenarios. |
| CRI / Ra | Unitless, 0–100 | Ability to render object colors accurately, Ra≥80 is good. | Affects color authenticity, used in high-demand places like malls, museums. |
| SDCM | MacAdam ellipse steps, e.g., "5-step" | Color consistency metric, smaller steps mean more consistent color. | Ensures uniform color across same batch of LEDs. |
| Dominant Wavelength | nm (nanometers), e.g., 620nm (red) | Wavelength corresponding to color of colored LEDs. | Determines hue of red, yellow, green monochrome LEDs. |
| Spectral Distribution | Wavelength vs intensity curve | Shows intensity distribution across wavelengths. | Affects color rendering and quality. |
Electrical Parameters
| Term | Symbol | Simple Explanation | Design Considerations |
|---|---|---|---|
| Forward Voltage | Vf | Minimum voltage to turn on LED, like "starting threshold". | Driver voltage must be ≥Vf, voltages add up for series LEDs. |
| Forward Current | If | Current value for normal LED operation. | Usually constant current drive, current determines brightness & lifespan. |
| Max Pulse Current | Ifp | Peak current tolerable for short periods, used for dimming or flashing. | Pulse width & duty cycle must be strictly controlled to avoid damage. |
| Reverse Voltage | Vr | Max reverse voltage LED can withstand, beyond may cause breakdown. | Circuit must prevent reverse connection or voltage spikes. |
| Thermal Resistance | Rth (°C/W) | Resistance to heat transfer from chip to solder, lower is better. | High thermal resistance requires stronger heat dissipation. |
| ESD Immunity | V (HBM), e.g., 1000V | Ability to withstand electrostatic discharge, higher means less vulnerable. | Anti-static measures needed in production, especially for sensitive LEDs. |
Thermal Management & Reliability
| Term | Key Metric | Simple Explanation | Impact |
|---|---|---|---|
| Junction Temperature | Tj (°C) | Actual operating temperature inside LED chip. | Every 10°C reduction may double lifespan; too high causes light decay, color shift. |
| Lumen Depreciation | L70 / L80 (hours) | Time for brightness to drop to 70% or 80% of initial. | Directly defines LED "service life". |
| Lumen Maintenance | % (e.g., 70%) | Percentage of brightness retained after time. | Indicates brightness retention over long-term use. |
| Color Shift | Δu′v′ or MacAdam ellipse | Degree of color change during use. | Affects color consistency in lighting scenes. |
| Thermal Aging | Material degradation | Deterioration due to long-term high temperature. | May cause brightness drop, color change, or open-circuit failure. |
Packaging & Materials
| Term | Common Types | Simple Explanation | Features & Applications |
|---|---|---|---|
| Package Type | EMC, PPA, Ceramic | Housing material protecting chip, providing optical/thermal interface. | EMC: good heat resistance, low cost; Ceramic: better heat dissipation, longer life. |
| Chip Structure | Front, Flip Chip | Chip electrode arrangement. | Flip chip: better heat dissipation, higher efficacy, for high-power. |
| Phosphor Coating | YAG, Silicate, Nitride | Covers blue chip, converts some to yellow/red, mixes to white. | Different phosphors affect efficacy, CCT, and CRI. |
| Lens/Optics | Flat, Microlens, TIR | Optical structure on surface controlling light distribution. | Determines viewing angle and light distribution curve. |
Quality Control & Binning
| Term | Binning Content | Simple Explanation | Purpose |
|---|---|---|---|
| Luminous Flux Bin | Code e.g., 2G, 2H | Grouped by brightness, each group has min/max lumen values. | Ensures uniform brightness in same batch. |
| Voltage Bin | Code e.g., 6W, 6X | Grouped by forward voltage range. | Facilitates driver matching, improves system efficiency. |
| Color Bin | 5-step MacAdam ellipse | Grouped by color coordinates, ensuring tight range. | Guarantees color consistency, avoids uneven color within fixture. |
| CCT Bin | 2700K, 3000K etc. | Grouped by CCT, each has corresponding coordinate range. | Meets different scene CCT requirements. |
Testing & Certification
| Term | Standard/Test | Simple Explanation | Significance |
|---|---|---|---|
| LM-80 | Lumen maintenance test | Long-term lighting at constant temperature, recording brightness decay. | Used to estimate LED life (with TM-21). |
| TM-21 | Life estimation standard | Estimates life under actual conditions based on LM-80 data. | Provides scientific life prediction. |
| IESNA | Illuminating Engineering Society | Covers optical, electrical, thermal test methods. | Industry-recognized test basis. |
| RoHS / REACH | Environmental certification | Ensures no harmful substances (lead, mercury). | Market access requirement internationally. |
| ENERGY STAR / DLC | Energy efficiency certification | Energy efficiency and performance certification for lighting. | Used in government procurement, subsidy programs, enhances competitiveness. |