SMD LED BR15-22C/L586/R/TR8 Datasheet - Package 3.2x1.6x1.1mm - Voltage 1.3-2.6V - Power 100-125mW - Infrared 905nm & Red 660nm - English Technical Document

1. Product Overview

The BR15-22C/L586/R/TR8 is a dual-emitter Surface-Mount Device (SMD) LED that integrates both an infrared (IR) and a red light-emitting diode within a single, miniature top-view flat package. The device is encapsulated in water-clear plastic, allowing for efficient light transmission. A key design feature is its spectral output, which is specifically matched to the sensitivity of silicon photodiodes and phototransistors, making it an ideal source for optical sensing and detection systems.

The core advantages of this component include a low forward voltage, which contributes to higher energy efficiency in circuit designs. It is manufactured to be lead-free (Pb-free) and complies with major environmental regulations including RoHS, EU REACH, and halogen-free standards (Br <900ppm, Cl <900ppm, Br+Cl <1500ppm), ensuring its suitability for modern, eco-conscious electronics manufacturing.

The primary target market and application is infrared-applied systems, such as proximity sensors, object detection, encoders, and other optoelectronic interfaces where reliable and matched light emission is critical.

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): 50 mA for both the IR and Red chips.
• Reverse Voltage (VR): 5 V. Exceeding this can cause junction breakdown.
• Operating Temperature (Topr): -40°C to +85°C. This defines the ambient temperature range for reliable operation.
• Storage Temperature (Tstg): -40°C to +100°C.
• Soldering Temperature (Tsol): 260°C for a maximum of 5 seconds, critical for reflow assembly processes.
• Power Dissipation (Pc): 100 mW for the IR emitter and 125 mW for the Red emitter at or below 25°C free air temperature. This parameter is crucial for thermal management design.

2.2 Electro-Optical Characteristics

These are the typical performance parameters measured at Ta=25°C, providing the expected behavior under normal operating conditions.

• Radiant Intensity (IE): For the IR emitter (BR), the typical value is 0.50 mW/sr at IF=20mA. For the Red emitter, it is 1.50 mW/sr at the same current. This measures the optical power emitted per solid angle.
• Peak Wavelength (λp): The IR emitter peaks at 905 nm, while the Red emitter peaks at 660 nm. This defines the dominant color of the emitted light.
• Spectral Bandwidth (Δλ): Approximately 30 nm for both emitters, indicating the spread of wavelengths around the peak.
• Forward Voltage (VF): The IR chip has a typical VF of 1.30V (max 1.80V), and the Red chip has a typical VF of 1.80V (max 2.60V) at IF=20mA. Low VF is a key feature for power efficiency.
• Reverse Current (IR): Maximum of 10 µA at VR=5V for both chips, indicating the leakage current in the off state.
• View Angle (2θ1/2): 140 degrees. This wide viewing angle is characteristic of the top-view, non-lensed package, providing broad emission.

3. Performance Curve Analysis

3.1 Infrared Emitter (905nm) Characteristics

The provided graphs illustrate the relationship between key parameters for the IR chip. The Radiant Intensity vs. Forward Current curve shows a near-linear increase in optical output with current up to the maximum rating. The Forward Current vs. Forward Voltage curve demonstrates the diode's exponential IV relationship, crucial for designing current-limiting circuits. The Spectral Distribution graph confirms the peak at 905nm with the defined bandwidth. The Forward Current vs. Ambient Temperature curve is essential for understanding derating requirements; as temperature increases, the maximum allowable continuous current decreases to prevent overheating.

3.2 Red Emitter (660nm) Characteristics

Similar curves are provided for the red emitter. Notably, the radiant intensity is higher for a given current compared to the IR emitter. The spectral graph shows a sharp peak at 660nm within the visible red spectrum. The electrical characteristics (IV curve) follow the same diode law but with a higher typical forward voltage.

3.3 Angular Characteristics

A graph titled Relative Light Current vs. Angular Displacement is referenced. This curve is vital for application design, showing how the intensity perceived by a detector changes with the angle between the LED and the detector. The 140-degree viewing angle is defined as the angle where intensity drops to half of its on-axis value.

4. Mechanical and Packaging Information

4.1 Package Dimensions

The device comes in a compact SMD package. Key dimensions (in mm) include a body length of approximately 3.2, width of 1.6, and height of 1.1. Detailed drawings specify pad layout, component outline, and tolerances (typically ±0.1mm unless otherwise noted), which are critical for PCB footprint design.

4.2 Polarity Identification

The package includes markings or a specific pad design (often a chamfered corner or a dot) to indicate the cathode. Correct polarity must be observed during assembly to prevent reverse bias damage.

4.3 Carrier Tape and Reel Specifications

The product is supplied on tape and reel for automated assembly. The carrier tape dimensions are specified, with a standard reel containing 2000 pieces. This information is necessary for setting up pick-and-place machines.

5. Soldering and Assembly Guidelines

5.1 Storage and Handling

The LEDs are moisture-sensitive. Precautions include: keeping the sealed moisture-proof bag unopened until use; storing unopened bags at ≤30°C/90%RH and using within one year; after opening, storing at ≤30°C/60%RH and using within 168 hours (7 days). If the storage time is exceeded, a baking treatment at 60±5°C for at least 24 hours is required.

5.2 Reflow Soldering

A Pb-free solder temperature profile is recommended. Reflow soldering should not be performed more than two times to avoid thermal stress. During heating, no mechanical stress should be applied to the LED body. The PCB should not be warped after soldering.

5.3 Hand Soldering

If hand soldering is necessary, use a soldering iron with a tip temperature below 350°C, apply heat to each terminal for no more than 3 seconds, and use an iron with a capacity of 25W or less. Allow a cooling interval of more than 2 seconds between soldering each terminal.

5.4 Rework and Repair

Repair after soldering is discouraged. If unavoidable, a double-head soldering iron should be used to simultaneously heat both terminals, minimizing thermal stress across the package. The potential for damage to LED characteristics must be evaluated beforehand.

6. Application Suggestions and Design Considerations

6.1 Typical Application Circuits

The most critical design rule is over-current protection. An external current-limiting resistor is mandatory. Due to the diode's exponential IV characteristic, a small increase in voltage can cause a large, destructive increase in current. The resistor value must be calculated based on the supply voltage (Vs), the desired forward current (If), and the LED's forward voltage (Vf) using the formula: R = (Vs - Vf) / If. Separate resistors are needed if the IR and red emitters are to be driven independently.

6.2 Thermal Management

While the power dissipation is low, proper PCB layout can aid heat dissipation. Ensure adequate copper area connected to the thermal pads (if any) or the device leads. Adhere to the power derating guidelines implied by the maximum ratings—operating at high ambient temperatures requires reducing the forward current.

6.3 Optical Design

Utilize the 140-degree wide viewing angle for applications requiring broad coverage. For longer-range or more directed sensing, external lenses or reflectors may be needed. The water-clear lens is suitable for applications where the exact chip emission pattern is desired without color filtering.

7. Technical Comparison and Differentiation

The primary differentiation of the BR15-22C/L586/R/TR8 lies in its dual-wavelength capability within a single, compact SMD package. This saves board space compared to using two separate LEDs. Its spectral matching to silicon detectors is optimized, potentially improving signal-to-noise ratio in sensing applications. The low forward voltage, especially for the IR emitter, offers an efficiency advantage. The compliance with stringent environmental standards (RoHS, REACH, Halogen-Free) makes it suitable for a wide range of global markets.

8. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive the IR and Red LEDs simultaneously at their maximum current of 50mA each?
A: No. The Absolute Maximum Rating for Continuous Forward Current is 50mA per chip. Driving both at 50mA simultaneously would likely exceed the total package power dissipation limits (Pc) and cause overheating. The drive currents must be derated based on the total power and thermal conditions.

Q: Why is a current-limiting resistor absolutely necessary?
A: An LED is a current-operated device. Its forward voltage changes slightly with current and temperature. Connecting it directly to a voltage source (even a regulated one) will cause the current to rise uncontrollably until the device fails, as there is no internal resistance to limit it. The resistor provides a stable, predictable current.

Q: What does \"spectrally matched to silicon photodetector\" mean?
A: Silicon photodiodes and phototransistors have a specific spectral response curve; they are most sensitive to certain wavelengths (typically in the near-infrared and red region). This LED's peak wavelengths (905nm IR and 660nm Red) are chosen to fall within the high-sensitivity zones of these detectors, maximizing the electrical signal generated for a given optical power.

Q: How do I interpret the \"View Angle\" of 140 degrees?
A: This is the full angle at which the radiant intensity drops to half (50%) of its value when measured directly on-axis (0 degrees). So, the emission is effectively usable within a very wide ±70-degree cone from the center.

9. Practical Design and Usage Case

Case: Designing a Proximity Sensor for a Mobile Device
The BR15-22C/L586/R/TR8 can be used in a proximity sensor to detect when an object (like a user's ear during a call) is near the phone. The IR emitter (905nm) is pulsed. A nearby silicon photodiode detects the reflected IR light. The red emitter is not used in this specific mode but could be utilized for other functions like a status indicator. The design steps include: 1) Calculating the current-limiting resistor for the IR LED based on the driver IC's output voltage and the desired pulse current (e.g., 20mA for good intensity). 2) Placing the LED and photodiode on the PCB with an optical barrier between them to prevent direct crosstalk. 3) Following the reflow soldering profile precisely to avoid damaging the moisture-sensitive package. 4) Implementing firmware that pulses the LED and reads the photodiode signal, using a threshold to determine \"near\" or \"far\" state.

10. Operating Principle Introduction

Light Emitting Diodes (LEDs) are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type region recombine with holes from the p-type region. This recombination releases energy in the form of photons (light). The specific wavelength (color) of the emitted light is determined by the bandgap energy of the semiconductor material used. The IR emitter uses Gallium Aluminum Arsenide (GaAlAs), which has a bandgap corresponding to 905nm infrared light. The red emitter uses Aluminum Gallium Indium Phosphide (AlGaInP), which produces 660nm red light. The water-clear epoxy lens encapsulates the chip, provides mechanical protection, and shapes the light output pattern.

11. Technology Trends and Context

The development of SMD LEDs like the BR15-22C/L586/R/TR8 is driven by trends in miniaturization, automation, and multifunctionality in electronics. The move to lead-free and halogen-free manufacturing reflects the global push for environmentally sustainable components. In sensing applications, there is a continuous demand for higher efficiency (more light output per electrical watt) and tighter spectral matching to improve system performance and reduce power consumption. The integration of multiple wavelengths or functions into single packages is a logical step to save space and cost in increasingly complex devices. Furthermore, improvements in package materials and design aim to enhance reliability under thermal stress and moisture exposure, which are critical for automotive, industrial, and consumer applications.