1. Product Overview
This document details the specifications for a discrete infrared component designed for applications requiring reliable infrared emission and detection. The device is a surface-mount component featuring a 940nm peak wavelength, making it suitable for a variety of optoelectronic systems.
1.1 Features
- Compliant with RoHS and Green Product standards.
- Packaged in 8mm tape on 7\" diameter reels for automated assembly.
- Compatible with automatic placement equipment and infrared reflow soldering processes.
- Standard EIA package footprint.
- Peak emission wavelength (λp) of 940nm.
- Water-clear plastic encapsulation with a top-view lens.
- Moisture Sensitivity Level (MSL) 3.
1.2 Applications
- Infrared emitter for remote control units.
- PCB-mounted infrared sensor for proximity sensing, data transmission, or security alarms.
2. Outline Dimensions
The component adheres to a standard surface-mount device (SMD) package outline. All primary dimensions are provided in the datasheet drawings with a standard tolerance of ±0.15mm unless otherwise specified. The package is designed for reliable placement and soldering on printed circuit boards.
3. Absolute Maximum Ratings
These ratings define the limits beyond which permanent damage to the device may occur. All values are specified at an ambient temperature (TA) of 25°C.
- Power Dissipation (Pd): 100 mW
- Peak Forward Current (IFP): 1 A (under pulsed conditions: 300 pps, 10μs pulse width)
- DC Forward Current (IF): 50 mA
- Reverse Voltage (VR): 5 V
- Operating Temperature Range (Topr): -40°C to +85°C
- Storage Temperature Range (Tstg): -55°C to +100°C
- Infrared Reflow Soldering Condition: Maximum peak temperature of 260°C for 10 seconds.
4. Electrical and Optical Characteristics
Typical performance parameters are measured at TA=25°C under specified test conditions, providing the expected operational behavior.
- Radiant Intensity (IE): 4.0 (Min), 6.0 (Typ) mW/sr at IF = 20mA.
- Peak Emission Wavelength (λPeak): 940 nm (Typ) at IF = 20mA.
- Spectral Line Half-Width (Δλ): 50 nm (Typ) at IF = 20mA.
- Forward Voltage (VF): 1.2 (Typ), 1.5 (Max) V at IF = 20mA.
- Reverse Current (IR): 10 μA (Max) at VR = 5V.
- Viewing Angle (2θ1/2): 20 (Min), 25 (Typ) degrees. θ1/2 is the off-axis angle where radiant intensity is half the axial value.
4.1 Bin Code List
The devices are grouped into bins based on measured Radiant Intensity at 20mA to ensure consistency in application design.
- Bin Code K: 4 to 6 mW/sr
- Bin Code L: 5 to 7.5 mW/sr
- Bin Code M: 6 to 9 mW/sr
- Bin Code N: 7 to 10.5 mW/sr
5. Typical Performance Curves
The following curves illustrate the device's behavior under various conditions, providing deeper insight for circuit design.
5.1 Spectral Distribution
The spectral output curve shows the relative radiant intensity across wavelengths, centered around the 940nm peak with a typical 50nm half-width, defining the infrared light's spectral purity.
5.2 Forward Current vs. Forward Voltage
This IV curve depicts the relationship between the forward current applied and the resulting voltage drop across the device, crucial for determining the necessary drive voltage and power dissipation.
5.3 Forward Current vs. Ambient Temperature
This graph shows the maximum allowable continuous forward current derating as the ambient temperature increases, essential for thermal management and reliability.
5.4 Relative Radiant Intensity vs. Forward Current
Illustrates how the optical output power scales with increasing drive current, helping to optimize the current setting for desired brightness/intensity.
5.5 Relative Radiant Intensity vs. Ambient Temperature
Shows the typical decrease in optical output as the junction temperature rises, which is a key consideration for applications operating in varying thermal environments.
5.6 Radiation Pattern Diagram
A polar plot representing the angular distribution of emitted infrared radiation, characterized by the 25-degree typical viewing angle. This defines the emission cone and is vital for aligning the emitter with a detector.
6. Mechanical and Packaging Information
6.1 Suggested Soldering Pad Layout
Recommended PCB land pattern dimensions are provided to ensure proper solder joint formation, mechanical stability, and thermal relief during the reflow process.
6.2 Tape and Reel Package Dimensions
Detailed drawings specify the carrier tape dimensions, pocket spacing, and reel specifications compatible with standard SMD assembly equipment.
- Reel diameter: 7 inches.
- Quantity per reel: 1500 pieces.
- Packaging conforms to ANSI/EIA 481-1-A-1994 specifications.
7. Assembly and Handling Guidelines
7.1 Storage Conditions
Due to its Moisture Sensitivity Level 3 rating, specific storage protocols must be followed. Unopened, factory-sealed packages with desiccant should be stored below 30°C and 90% RH and used within one year. Once opened, components should be stored below 30°C and 60% RH and ideally reflowed within one week. Extended storage outside the original bag requires a dry cabinet or sealed container with desiccant. Components stored for over a week should be baked at approximately 60°C for at least 20 hours before soldering to prevent \"popcorning\" damage.
7.2 Cleaning
If cleaning is necessary after soldering, only alcohol-based solvents like isopropyl alcohol (IPA) should be used. Harsh or aggressive chemical cleaners must be avoided.
7.3 Soldering Recommendations
The device is compatible with infrared reflow soldering. A JEDEC-compliant temperature profile is recommended.
- Reflow Soldering: Maximum peak temperature of 260°C for a maximum of 10 seconds (max two reflow cycles).
- Hand Soldering (Iron): Maximum tip temperature of 300°C for a maximum of 3 seconds per pad.
The exact profile should be characterized for the specific PCB design, solder paste, and oven used.
7.4 Drive Circuit Design
As an infrared emitting diode (IRED) is a current-driven device, a series current-limiting resistor is mandatory for stable operation. The recommended circuit configuration (Circuit A) places an individual resistor in series with each IRED, even when multiple devices are connected in parallel to a voltage source. This ensures uniform current distribution and consistent radiant intensity across all devices, preventing brightness variations that can occur in a simple parallel connection without individual resistors (Circuit B).
8. Application Notes and Design Considerations
8.1 Typical Application Scenarios
This component is designed for general-purpose infrared applications. Its 940nm wavelength is ideal for remote control systems due to its high transmission through many plastics and low visibility. It is also suitable for short-range data links, object detection, and proximity sensing in consumer electronics, office equipment, and basic industrial controls.
8.2 Design Considerations
- Optical Alignment: The 25-degree viewing angle requires careful mechanical alignment between the emitter and the corresponding photodetector (e.g., phototransistor or photodiode) for optimal signal strength.
- Current Setting: Operate at or below the recommended 20mA DC forward current for testing key parameters. Use the performance curves to select the appropriate current for the required radiant intensity while considering power dissipation and thermal effects.
- Ambient Light Immunity:
- When used as part of a sensing system, consider the use of modulated IR signals and corresponding filtered detectors to reject interference from ambient light sources like sunlight or incandescent bulbs.
- Thermal Management: Ensure the PCB layout provides adequate thermal relief, especially if operating near maximum ratings or in high ambient temperatures, to maintain long-term reliability.
8.3 Principle of Operation
The device functions as an infrared light-emitting diode (LED). When a forward bias voltage exceeding its forward voltage (VF) is applied, electrons and holes recombine in the semiconductor junction, releasing energy in the form of photons. The specific semiconductor materials (e.g., GaAs) are chosen to produce photons in the infrared spectrum (940nm), which is invisible to the human eye but can be detected by silicon-based photodetectors.
9. Frequently Asked Questions (Based on Technical Parameters)
9.1 What is the difference between Radiant Intensity and Luminous Intensity?
Radiant Intensity (measured in mW/sr) is the optical power emitted per solid angle in the infrared spectrum. Luminous Intensity (measured in candela) is weighted by the sensitivity of the human eye and is not applicable for this non-visible infrared source.
9.2 Can I drive this IRED directly from a microcontroller GPIO pin?
No. A microcontroller pin typically cannot source 20mA reliably and lacks current regulation. Always use a driver circuit (like a transistor) with a series current-limiting resistor as shown in the datasheet to provide a stable, controlled current to the IRED.
9.3 Why is the storage condition so specific (MSL 3)?
The plastic packaging can absorb moisture from the air. During the high-temperature reflow soldering process, this trapped moisture can rapidly vaporize, creating internal pressure and potentially causing delamination or cracks (\"popcorning\"). The MSL rating and baking instructions prevent this failure mode.
9.4 How do I select the correct series resistor value?
Use Ohm's Law: R = (Vsupply - VF) / IF. For example, with a 5V supply, a typical VF of 1.2V, and a desired IF of 20mA: R = (5 - 1.2) / 0.02 = 190 Ohms. Choose the nearest standard resistor value, considering power rating (P = I2R).
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. |