Table of Contents
- 1. Product Overview
- 1.1 Core Advantages
- 1.2 Target Applications
- 2. In-Depth Technical Parameter Analysis
- 2.1 Absolute Maximum Ratings
- 2.2 Electro-Optical Characteristics
- 3. Binning System Explanation
- 3.1 Radiant Intensity Binning
- 4. Performance Curve Analysis
- 4.1 Forward Current vs. Forward Voltage (Fig.4)
- 4.2 Relative Intensity vs. Ambient Temperature (Fig.7)
- 4.3 Spectral Distribution & Peak Wavelength vs. Temperature (Fig.2 & Fig.3)
- 4.4 Angular Radiation Pattern (Fig.6)
- 5. Mechanical and Package Information
- 5.1 Package Dimensions
- 5.2 Polarity Identification
- 6. Soldering and Assembly Guidelines
- 7. Packaging and Ordering Information
- 7.1 Packing Specifications
- 7.2 Label Information
- 8. Application Design Recommendations
- 8.1 Driving Circuit Design
- 8.2 Thermal Considerations
- 8.3 Optical Design
- 9. Technical Comparison and Differentiation
- 10. Frequently Asked Questions (Based on Technical Parameters)
- 11. Practical Design and Usage Examples
- 11.1 Long-Range Infrared Remote Control
- 11.2 Proximity or Object Detection Sensor
- 12. Operating Principle
- 13. Technology Trends
1. Product Overview
IR204C-A wata ce mai ƙarfi mai fitar da hasken infrared da ke cikin daidaitaccen fakitin filastik mai tsabta na ruwa na 3mm (T-1). Babban aikinta shine fitar da hasken infrared a tsayin tsayin raƙuman ruwa na 940nm, wanda ya sa ta dace da na'urorin gani na silicon na yau da kullun, photodiodes, da kuma na'urorin karɓar infrared. An ƙera wannan na'urar don aikace-aikacen da ke buƙatar amintaccen da ingantaccen watsa infrared.
1.1 Core Advantages
- Babban Ƙarfin Haskakawa: Delivers strong optical output, suitable for medium to long-range applications.
- High Reliability: Engineered for stable and long-term performance.
- Low Forward Voltage: Typically 1.5V at 20mA, contributing to energy-efficient operation.
- Environmental Compliance: The product is Pb-free, compliant with EU REACH, and meets halogen-free standards (Br < 900ppm, Cl < 900ppm, Br+Cl < 1500ppm).
- Standard Package: O le foliga masani T-1 (3mm) ma le 2.54mm lead spacing e mautinoa ai le faigofie ona tuʻufaʻatasia i mamanu o loʻo iai ma laupapa faʻataʻitaʻi.
1.2 Target Applications
- Infrared remote control units with high power requirements.
- Free-air optical data transmission systems.
- Smoke detection sensors.
- General infrared sensing and barrier systems.
- Industrial automation and object detection.
2. In-Depth Technical Parameter Analysis
This section provides a detailed, objective interpretation of the key electrical and optical parameters specified in the datasheet. Understanding these limits and typical values is crucial for robust circuit design.
2.1 Absolute Maximum Ratings
These are stress limits that must not be exceeded under any conditions, even momentarily. Operation beyond these ratings may cause permanent damage.
- Continuous Forward Current (IF): 100 mA. LED inaweza kutumika kwa mfululizo kwa kiwango hiki cha sasa, mradi utoaji wa nguvu na mipaka ya joto zizingatiwe.
- Peak Forward Current (IFP): 1.0 A. Wannan babban yanzu yana halatta ne kawai a ƙarƙashin yanayin bugun jini (faɗin bugun ≤ 100μs, zagayowar aiki ≤ 1%). Wannan yana da amfani don cimma fitar da haske mai tsananin ƙarfi a cikin aikace-aikacen fashewa kamar na'urorin sarrafa nesa mai nisa.
- Reverse Voltage (VR): 5 V. LED ɗin yana da iyakataccen juriya na ƙarfin juzu'i. Dole ne a kula a cikin ƙirar da'ira don hana jujjuyawar baya fiye da wannan iyaka, wanda zai iya haifar da nauyin inductive ko rashin daidaitawar wutar lantarki.
- Power Dissipation (Pd): 150 mW a ko ƙasa da zafin iska 25°C. Wannan ƙimar tana raguwa yayin da yanayin yanayi ya ƙaru. Dole ne a rage ainihin yanzu na aiki bisa ga zafin haɗin gwiwa don tsayawa cikin iyakoki masu aminci.
- Soldering Temperature (Tsol): 260°C for a maximum of 5 seconds. This defines the reflow soldering profile constraints.
2.2 Electro-Optical Characteristics
These parameters define the device's performance under normal operating conditions (Ta=25°C).
- Radiant Intensity (Ie): This is the primary measure of optical output power per solid angle (mW/sr).
- At IF = 20mA (DC): Typical value is 7.8 mW/sr, with a minimum of 4.0 mW/sr.
- At IF = 100mA (Pulsed): Typical radiant intensity rises significantly.
- At IF = 1A (Pulsed): Can deliver a typical output of 390 mW/sr, showcasing its capability for high-power pulsed operation.
- Peak Wavelength (λp): 940 nm (typical). Wannan tsayin raɗaɗin yana da kyau sosai saboda ya yi daidai da mafi girman hankalin na'urorin gano haske na tushen silicon, yayin da ba a iya ganinsa da ido na ɗan adam kuma yana da kyakkyawan watsa iska.
- Faɗin Bakan Raɗaɗi (Δλ): Kusan 45 nm (typical). Wannan yana ayyana faɗin bakan raɗaɗin hasken da ake fitarwa a rabin mafi girman ƙarfinsa (FWHM).
- Ƙarfin Wutar Gaba (VF):
- At 20mA: 1.5V typical, 1.2V min, crucial for calculating series resistor values.
- At 100mA (pulsed): 1.4V typical, 1.8V max. VF increases with current due to diode resistance.
- At 1A (pulsed): 2.6V typical, 4.0V max, showing significant increase under high-current pulse conditions.
- Viewing Angle (2θ1/2): 40 degrees (typical). This is the full angle at which the radiant intensity drops to half of its on-axis value. A 40° angle provides a good balance between beam concentration and coverage.
3. Binning System Explanation
The datasheet includes a binning table for radiant intensity, which is a common practice to categorize LEDs based on measured performance.
3.1 Radiant Intensity Binning
Under the condition IF = 20mA, the LEDs are sorted into bins (K, L, M, N) based on their measured radiant intensity.
- Bin K: 4.0 - 6.4 mW/sr
- Bin L: 5.6 - 8.9 mW/sr
- Bin M: 7.8 - 12.5 mW/sr
- Bin N: 11.0 - 17.6 mW/sr
Design Implication: For applications requiring consistent optical signal strength (e.g., remote controls with a defined range), specifying a tighter bin (like a single bin) or a higher minimum bin ensures more uniform performance across production units. The bin code is typically indicated in the ordering information or on the product label.
4. Performance Curve Analysis
The typical characteristic curves provide valuable insights into the device's behavior under varying conditions.
4.1 Forward Current vs. Forward Voltage (Fig.4)
This IV curve shows the exponential relationship. The curve will shift with temperature; forward voltage typically decreases as junction temperature increases for a given current.
4.2 Relative Intensity vs. Ambient Temperature (Fig.7)
This graph is critical for thermal management. The radiant output of an LED decreases as its junction temperature rises. The curve quantifies this derating, informing designers that higher ambient temperatures or inadequate heat sinking will result in lower optical output. This must be accounted for in systems designed to operate over the full -40°C to +85°C range.
4.3 Spectral Distribution & Peak Wavelength vs. Temperature (Fig.2 & Fig.3)
Fig.2 shows the typical emission spectrum centered at 940nm. Fig.3 illustrates how the peak wavelength shifts with temperature. Infrared LEDs typically exhibit a positive temperature coefficient for wavelength (i.e., λp increases with temperature). This shift is important in applications where the detector has a narrow spectral response.
4.4 Angular Radiation Pattern (Fig.6)
This polar plot depicts the relative radiant intensity as a function of angular displacement from the central axis. The 40° viewing angle is confirmed here. The pattern is generally Lambertian or near-Lambertian for this package type, meaning intensity is approximately proportional to the cosine of the viewing angle.
5. Mechanical and Package Information
5.1 Package Dimensions
The device uses a standard T-1 (3mm diameter) round package. Key dimensional notes from the datasheet include:
- All dimensions are in millimeters (mm).
- Standard tolerances are ±0.25mm unless otherwise specified.
- Lead spacing is 2.54mm (0.1 inches), compatible with standard perforated boards and many sockets.
5.2 Polarity Identification
For a standard T-1 LED, the cathode is typically identified by a flat spot on the plastic lens rim and/or by the shorter lead. The datasheet should be consulted for the specific marking of this part.
6. Soldering and Assembly Guidelines
- Reflow Soldering: The maximum soldering temperature is 260°C, and the time at or above this temperature must not exceed 5 seconds. A standard lead-free reflow profile is applicable.
- Hand Soldering: If hand soldering is necessary, a temperature-controlled iron should be used, and the soldering time per lead should be minimized (typically < 3 seconds at 350°C) to prevent thermal damage to the plastic package and the semiconductor die.
- Storage Conditions: The storage temperature range is -40°C to +85°C. Components should be kept in their original moisture-barrier bags until use to prevent moisture absorption, which can cause "popcorning" during reflow.
7. Packaging and Ordering Information
7.1 Packing Specifications
- Standard packing: 200 to 1000 pieces per bag.
- 5 bags are packed into 1 box.
- 10 boxes are packed into 1 carton.
7.2 Label Information
The product label contains key traceability and specification data:
- CPN (Customer Part Number)
- P/N (Manufacturer Part Number: IR204C-A)
- QTY (Packing Quantity)
- Ranks/Bin Codes (e.g., for Radiant Intensity)
- HUE (Peak Wavelength information)
- LOT No. (Traceable lot number)
8. Application Design Recommendations
8.1 Driving Circuit Design
The LED must be driven with a current-limiting element, typically a resistor in series with a voltage source. The resistor value (Rs) is calculated as: Rs = (Vsupply - VF) / IF. Use the maximum VF from the datasheet for the chosen operating current to ensure the current does not exceed the desired value. For example, for a 5V supply and a target IF of 20mA using the max VF of 1.5V: Rs = (5 - 1.5) / 0.02 = 175 Ω. A standard 180 Ω resistor would be suitable. For pulsed operation at high currents, a transistor switch (BJT or MOSFET) is required.
8.2 Thermal Considerations
While the T-1 package has limited thermal dissipation capability, at continuous currents up to 100mA, ensuring adequate airflow or considering the power dissipation (Pd = VF * IF) is important. If operated continuously near the maximum current in a high ambient temperature, the junction temperature may rise, reducing output and potentially affecting longevity.
8.3 Optical Design
The water-clear lens is suitable for use with external lenses or reflectors to collimate or shape the beam for specific applications like long-range transmission. The 940nm wavelength is well-transmitted by many common plastics used in lenses and windows.
9. Technical Comparison and Differentiation
The IR204C-A positions itself with key differentiators:
- High Pulsed Power Capability: The 1A peak current rating allows for very high instantaneous optical output, an advantage over LEDs rated only for lower pulsed currents.
- Standardized Package with Performance: It offers higher radiant intensity in the common, easy-to-use T-1 package compared to many basic infrared LEDs.
- Environmental Compliance: Full compliance with modern environmental regulations (RoHS, REACH, Halogen-Free) is a significant advantage for products targeting global markets.
- Spectral Matching: The explicit mention of being spectrally matched to common detectors simplifies the selection process for designers building complete optical systems.
10. Frequently Asked Questions (Based on Technical Parameters)
- Q: Can I drive this LED directly from a 3.3V microcontroller pin?
A: No. A microcontroller pin cannot source 20mA continuously safely, and it lacks current limiting. You must use a series resistor and a transistor switch. The LED's VF (1.5V) is less than 3.3V, so it is compatible voltage-wise, but current must be controlled externally. - Q: What is the difference between Radiant Intensity (mW/sr) and Radiant Power (mW)?
A: Radiant Intensity is angular density—power per unit solid angle. Radiant Power (or Flux) is the total power emitted in all directions. To find total power, you would integrate the intensity over the entire emission pattern. The datasheet provides intensity, which is more useful for calculating irradiance at a distance in a given direction. - Q: Why is the peak wavelength 940nm preferred over 850nm?
A: 940nm ba a iya ganinsa da sauƙi ga idon mutum (haske ja mai duhu) fiye da 850nm, wanda ya sa ba ya dagula hankali sosai a cikin na'urorin masu amfani. Dukansu silicon yana gano su da kyau, amma 940nm na iya samun ɗan ƙaramin tsangwama daga hasken yanayi daga wasu tushe kamar hasken rana da kwan fitila, waɗanda ke da ƙarfin fitarwa a yankin 850nm. - Q: Yaya zan zaɓi kwandon da ya dace?
A: Idan aikace-aikacenku yana da mafi ƙarancin ƙarfin siginar da ake buƙata a mai karɓa, yi amfani da mafi ƙarancin ƙimar kwandon don tabbatar duk sassan sun cika shi. Misali, idan kuna buƙatar aƙalla 6 mW/sr, ƙayyade Bin L ko mafi girma. Don aikace-aikacen masu kula da farashi inda wasu bambance-bambance suka yarda, kwandon mai faɗi ko bayarwar ta asali na iya isa.
11. Practical Design and Usage Examples
11.1 Long-Range Infrared Remote Control
Scenario: Designing a remote control that must work reliably at a distance of 15 meters in a moderately lit living room.
Implementation: Use the LED in pulsed mode. Drive it with short (e.g., 50μs), high-current pulses (e.g., 500mA) using a MOSFET switch controlled by an encoder IC. This delivers high peak radiant intensity (refer to the 1A pulsed data) for long-range transmission while keeping average power low. A simple plastic lens can be added to collimate the beam further. The 940nm wavelength minimizes visible glow.
11.2 Proximity or Object Detection Sensor
Scenario: Hana i se faiga e iloa ai mea e le pa'i atu i ai, e iai le mamao e 10-50 cm.
Implementation: Fa'atasi le IR204C-A ma se phototransistor e fetaui lelei. Fa'aola le LED i se ala faifaipea e feololo (fa'ata'ita'iga, 50mA) e fa'aaoga ai se puna o le ala tumau mo se malamalama mautu. Fa'aopoopo le ala o le LED i se taimi fa'apitoa (fa'ata'ita'iga, 38kHz) ma fa'aaoga se tali ua fa'atulaga lelei i le itu o le phototransistor. O lenei metotia fa'aopoopo e matua puipuia ai le faiga mai suiga o le malamalama o le si'osi'omaga (pei o le la po'o moli o le potu), e fa'aleleia atili ai le tulaga o le fa'ailo ma le fa'amaoni.
12. Operating Principle
An Infrared Light Emitting Diode (IR LED) is a semiconductor p-n junction diode. When forward biased, electrons from the n-region recombine with holes from the p-region in the active region. For an infrared LED like the IR204C-A, the energy bandgap of the semiconductor material (typically Gallium Aluminum Arsenide - GaAlAs as indicated) is such that the energy released during this recombination process corresponds to a photon in the infrared spectrum (around 940nm wavelength). The water-clear epoxy package acts as a lens, shaping the emitted light into the characteristic viewing angle. The intensity of the emitted light is directly proportional to the forward current flowing through the diode, up to the device's physical limits.
13. Technology Trends
Infrared LED technology continues to evolve alongside visible LED technology. Key trends influencing devices like the IR204C-A include:
- Increased Efficiency: Ongoing material science research aims to improve the wall-plug efficiency (optical power out / electrical power in) of IR LEDs, allowing for higher output at lower drive currents or reduced heat generation.
- Higher Power Density: Development of chip-scale packages and improved thermal management materials enables IR LEDs to handle higher continuous and pulsed currents in smaller form factors.
- Integration: There is a trend towards integrating the IR emitter with a driver IC, photodetector, or even a microcontroller into single modules for specific applications (e.g., proximity sensors, gesture recognition).
- Wavelength Precision and Stability: Advances in epitaxial growth techniques allow for tighter control over peak wavelength and spectral width, which is critical for applications like gas sensing or optical communications that use wavelength-division multiplexing.
- Expanding Application Space: The growth of areas like LiDAR for automotive/robotics, facial recognition, and health monitoring (e.g., pulse oximetry) drives demand for high-performance, reliable IR emitters across various wavelengths and power levels.
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: kona mafuta bora, ufanisi wa juu, kwa nguvu kubwa. |
| 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. | E kia mau tonu te tūrama i roto i te pātaka kotahi. |
| 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. |