Mini-Top Infrared LED HIR67-21C/L11/TR8 Datasheet - 850nm Peak Wavelength - 120° View Angle - 65mA Forward Current - English Technical Document

1. Product Overview

The HIR67-21C/L11/TR8 is a high-performance infrared (IR) emitting diode designed for surface-mount applications. It is housed in a miniature, flat-top SMD package molded from water-clear plastic, which acts as a lens. The device is engineered to emit light at a peak wavelength of 850nm, making it spectrally matched with common silicon photodiodes and phototransistors. This alignment is crucial for maximizing detection efficiency in optoelectronic systems.

Its core advantages include a low forward voltage, which contributes to energy efficiency, and compatibility with standard infrared and vapor phase reflow soldering processes. The component is also compliant with key environmental and safety standards, being Pb-free, RoHS compliant, EU REACH compliant, and halogen-free, meeting specific thresholds for bromine and chlorine content.

The target market for this IR LED spans various consumer and industrial electronics sectors where reliable, non-visible light sensing is required.

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation under these conditions is not guaranteed.

• Continuous Forward Current (IF): 65 mA. This is the maximum DC current that can be continuously passed through the LED.
• Reverse Voltage (VR): 5 V. Exceeding this reverse bias voltage can cause junction breakdown.
• Operating & Storage Temperature (Topr, Tstg): -40°C to +100°C. This wide range ensures reliability in harsh environments.
• Soldering Temperature (Tsol): 260°C for a maximum of 5 seconds, compatible with lead-free reflow profiles.
• Power Dissipation (Pd): 130 mW at or below 25°C ambient temperature. Power derating is necessary at higher temperatures.

2.2 Electro-Optical Characteristics (Ta=25°C)

These parameters define the device's performance under typical operating conditions.

• Radiant Intensity (Ie): Typically 2.0 mW/sr at a forward current (IF) of 20mA. Under pulsed operation (100μs pulse width, ≤1% duty cycle) at 100mA, it can reach 10 mW/sr.
• Peak Wavelength (λp): 850 nm (typical). This is the wavelength at which the emitted optical power is maximum.
• Spectral Bandwidth (Δλ): 45 nm (typical). This indicates the range of wavelengths emitted, centered around the peak.
• Forward Voltage (VF): Typically 1.45V at 20mA, with a maximum of 1.65V. At 100mA (pulsed), it ranges from 1.80V to 2.40V.
• Reverse Current (IR): Maximum 10 μA at a reverse voltage of 5V.
• View Angle (2θ1/2): 120 degrees (typical). This is the full angle at which the radiant intensity drops to half of its maximum value, indicating a very wide beam pattern.

3. Performance Curve Analysis

The datasheet provides several characteristic curves essential for circuit design and thermal management.

3.1 Power Dissipation vs. Ambient Temperature

This graph shows how the maximum allowable power dissipation decreases as the ambient temperature increases. Designers must use this curve to ensure the LED operates within its safe operating area, especially in high-temperature applications. The derating is linear, starting from 130mW at 25°C and reaching zero at the maximum junction temperature.

3.2 Spectral Distribution

The spectral distribution curve plots relative intensity against wavelength. It confirms the peak emission at 850nm and the approximately 45nm spectral bandwidth. This information is vital for selecting matching photodetectors and optical filters.

3.3 Forward Current vs. Forward Voltage (IV Curve)

This non-linear relationship is critical for designing the current-limiting circuitry. The curve shows that a small increase in voltage beyond the typical VF can lead to a large, potentially damaging increase in current, underscoring the need for proper current regulation (e.g., a series resistor or constant current driver).

3.4 Relative Radiant Intensity vs. Angular Displacement

This polar plot visually represents the 120-degree view angle. The intensity is highest at 0 degrees (perpendicular to the LED surface) and symmetrically decreases to 50% of its maximum at ±60 degrees from the center.

4. Mechanical and Packaging Information

4.1 Package Dimensions

The LED is provided in a compact SMD package. Key dimensions include the body size, lead spacing, and overall height. All dimensions are in millimeters with a standard tolerance of ±0.1mm unless otherwise specified. The flat top lens design contributes to the wide viewing angle.

4.2 Polarity Identification

The cathode is typically indicated by a marking on the package, such as a notch, dot, or trimmed lead. Correct polarity must be observed during assembly to prevent reverse bias damage.

4.3 Carrier Tape and Reel Specifications

The components are supplied in 8mm tape on 7-inch diameter reels, standard for automated pick-and-place assembly. Each reel contains 2000 pieces. Detailed carrier tape dimensions (pocket size, pitch, etc.) are provided to ensure compatibility with automated assembly equipment.

5. Soldering and Assembly Guidelines

5.1 Storage and Moisture Sensitivity

The LEDs are moisture-sensitive (MSL). Precautions include:

• Do not open the moisture-proof bag until ready for use.
• Store unopened bags at ≤30°C and ≤90% RH. Use within one year.
• After opening, use components within 168 hours (7 days) when stored at ≤30°C and ≤70% RH.
• If the storage time is exceeded or the desiccant indicates moisture, bake at 60±5°C for 24 hours before use.

5.2 Reflow Soldering

A recommended lead-free reflow temperature profile is provided. Key points:

• Peak temperature should not exceed 260°C.
• Time above liquidus (e.g., 217°C) should be controlled.
• Reflow should not be performed more than two times.
• Avoid mechanical stress on the package during heating and cooling.

5.3 Hand Soldering and Repair

If hand soldering is necessary:

• Use a soldering iron with a tip temperature <350°C.
• Limit contact time to ≤3 seconds per terminal.
• Use an iron with a power rating ≤25W.
• Allow a cooling interval of ≥2 seconds between soldering each terminal.
• Avoid repairing soldered LEDs. If unavoidable, use a double-head soldering iron to simultaneously heat both terminals and minimize thermal stress. Verify device functionality after any repair attempt.

6. Application Suggestions

6.1 Typical Application Scenarios

The datasheet lists several applications, including:

• Floppy Disk Drives & VCRs: For position sensing and end-of-tape detection.
• Optoelectronic Switches: Used in object detection, counting, and position sensing by pairing the IR LED with a phototransistor or photodiode.
• Cameras: Often used in autofocus systems or infrared illumination for night vision.
• Smoke Detectors: Employed in obscuration-type detectors where smoke particles interrupt an IR beam between an LED and a sensor.

6.2 Design Considerations

Current Limiting: This is the most critical design aspect. An external series resistor is mandatory to set the operating current and protect the LED from overcurrent caused by minor voltage fluctuations. The resistor value (R) can be calculated using Ohm's Law: R = (Vsupply - VF) / IF, where VF is the forward voltage from the datasheet at the desired current IF.
Thermal Management: For continuous operation near the maximum current rating or in high ambient temperatures, consider PCB layout for heat dissipation. Ensure the power dissipation (Pd = VF * IF) does not exceed the derated maximum from the Power Dissipation vs. Temperature curve.
Optical Design: The 120° wide beam is suitable for applications requiring broad coverage. For more focused beams, external lenses or reflectors may be needed. Ensure the housing material is transparent to 850nm IR light.

7. Technical Comparison and Differentiation

While the datasheet does not compare specific competitor parts, the HIR67-21C/L11/TR8 offers a combination of features that position it well in the market:

• Wide View Angle (120°): Offers broader coverage than many standard IR LEDs, which often have view angles around 20-60 degrees.
• Low Forward Voltage: Contributes to lower power consumption and reduced heat generation compared to LEDs with higher VF.
• Environmental Compliance: Its Pb-free, RoHS, REACH, and halogen-free status meets stringent global regulatory requirements, which is a key differentiator for modern electronics manufacturing.
• High Pulsed Output: The ability to deliver 10 mW/sr under pulsed operation (100mA) makes it suitable for applications requiring high instantaneous signal strength, like certain sensing or communication protocols.

8. Frequently Asked Questions (Based on Technical Parameters)

Q: Why is a current-limiting resistor absolutely necessary?
A: The IV curve shows the LED's exponential current-voltage relationship. A small increase in supply voltage beyond the nominal VF causes a very large, potentially destructive increase in current. A series resistor provides a linear voltage drop, stabilizing the current and protecting the LED.

Q: Can I drive this LED directly from a 3.3V or 5V microcontroller pin?
A: No. Microcontroller pins have limited current sourcing/sinking capability (often 20-40mA) and are not designed for driving power LEDs directly. Furthermore, you still need a series resistor. Use the microcontroller pin to control a transistor or MOSFET that switches the higher current required by the LED.

Q: What does "spectrally matched with silicon photodiode" mean?
A: Silicon photodetectors have peak sensitivity in the near-infrared region, around 800-900nm. The 850nm peak wavelength of this LED falls within this high-sensitivity zone, ensuring maximum conversion of emitted light into electrical current by the detector, leading to optimal system signal-to-noise ratio.

Q: How do I interpret the "Pulse Width ≦100μs , Duty≦1%" condition for the 100mA test?
A: This means the higher radiant intensity and forward voltage values at 100mA are only valid when the LED is pulsed, not driven with DC. The pulse must be 100 microseconds or shorter, and the time between pulses must be long enough that the average duty cycle is 1% or less (e.g., one 100μs pulse every 10ms). This prevents excessive heating.

9. Practical Design and Usage Case

Case: Designing a Simple Object Detection Sensor.
Goal: Detect when an object passes between an IR LED and a phototransistor.
Components: HIR67-21C/L11/TR8 IR LED, matching silicon phototransistor, resistors, comparator/op-amp, or microcontroller.
Steps:

1. LED Driver Circuit: Power the LED from a 5V supply. Choose an operating current, e.g., 20mA for good intensity and longevity. Calculate the series resistor: R = (5V - 1.45V) / 0.020A = 177.5Ω. Use a standard 180Ω resistor. Verify power dissipation in the resistor and LED is acceptable.
2. Detector Circuit: Place the phototransistor opposite the LED, aligned. When the IR beam is uninterrupted, the phototransistor conducts, creating a voltage drop across a load resistor. When an object blocks the beam, the phototransistor stops conducting, and the voltage changes.
3. Signal Conditioning: This voltage change can be fed into a comparator to create a clean digital signal, or directly into a microcontroller's analog-to-digital converter (ADC) pin for more sophisticated processing.
4. Considerations: Shield the setup from ambient light (which contains IR) to prevent false triggers. The 120° beam of the LED helps with alignment tolerance but may require a tube or barrier to define the sensing path more precisely.

10. Principle Introduction

Infrared Light Emitting Diodes (IR LEDs) operate on the same fundamental principle as visible LEDs: electroluminescence in a semiconductor material. When a forward voltage is applied across the p-n junction, electrons from the n-region recombine with holes from the p-region. This recombination event releases energy. In an IR LED, the semiconductor material (in this case, Gallium Aluminum Arsenide - GaAlAs) is chosen so that the energy bandgap corresponds to the emission of photons in the infrared spectrum (wavelengths longer than visible red light, typically 700nm to 1mm). The 850nm wavelength is in the "near-infrared" (NIR) region, which is invisible to the human eye but easily detectable by silicon-based sensors. The flat-top clear epoxy package serves both as an environmental seal and as a lens to shape the emitted light's radiation pattern.

11. Development Trends

The field of infrared optoelectronics continues to evolve. Key trends relevant to components like the HIR67-21C/L11/TR8 include:

• Increased Efficiency: Ongoing material science research aims to develop semiconductor structures with higher internal quantum efficiency (more photons per electron) and improved light extraction from the package, leading to higher radiant intensity for the same input power.
• Miniaturization: The drive for smaller, denser electronics pushes for even more compact SMD packages while maintaining or improving optical performance and thermal characteristics.
• Enhanced Wavelength Options: While 850nm and 940nm are common, there is development in other NIR wavelengths for specific applications, such as 810nm for medical devices or specific bands for gas sensing.
• Integration: Trends include integrating the IR LED with a driver IC or even with the photodetector in a single package to create complete, calibrated sensor modules, simplifying system design for end-users.
• Stricter Compliance: Environmental and material regulations (RoHS, REACH, halogen-free) will continue to become more stringent, driving the development of new packaging materials and manufacturing processes that meet these requirements without compromising performance or reliability.