Infrared LED Emitter 5mm Water Clear Package - Dimensions 5.0mm Dia x 8.6mm H - Forward Voltage 1.6-2.0V - Peak Wavelength 850nm - Radiant Intensity 30-45mW/sr - English Technical Datasheet

1. Product Overview

This document details the specifications for a discrete infrared light-emitting diode (IRED) designed for a broad range of optoelectronic applications. The device is engineered to deliver high radiant output with a low forward voltage characteristic, making it suitable for power-sensitive designs. Its primary emission is in the near-infrared spectrum, centered at a peak wavelength of 850 nanometers.

The core advantages of this component include its capability for high-current operation, which directly translates to high optical power output. It is packaged in a standard 5mm format with a water-clear lens, providing a wide viewing angle for broad area illumination or reception. This makes it a versatile choice for systems requiring reliable infrared signaling.

The target market and typical application scenarios encompass consumer electronics, industrial controls, and security systems. Common uses include infrared remote controls for televisions and audio equipment, short-range wireless data links, intrusion detection sensors in security alarms, and optical encoders. Its performance parameters are optimized for pulsed operation, which is standard in remote control and data transmission protocols.

2. In-Depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

Operating the device beyond these limits may cause permanent damage. The maximum continuous forward current is rated at 80 mA, with a peak forward current of 1 A permissible under pulsed conditions (300 pps, 10μs pulse width). The maximum power dissipation is 200 mW, which dictates the thermal design of the application. The device can withstand a reverse voltage of up to 5V, though it is not designed for operation in this regime. The operating and storage temperature ranges are -40°C to +85°C and -55°C to +100°C, respectively, ensuring reliability across harsh environments. Lead soldering must be performed at 260°C for a maximum of 5 seconds, with the iron tip positioned at least 1.6mm from the epoxy body.

2.2 Electrical and Optical Characteristics

Key performance parameters are measured at a standard test condition of a 50 mA forward current (I_F) and an ambient temperature (T_A) of 25°C.

• Radiant Intensity (I_E): The optical power output per solid angle, ranging from a minimum of 30 mW/sr to a typical value of 45 mW/sr. This is a direct measure of the LED's brightness in its primary direction.
• Peak Emission Wavelength (λ_P): The nominal wavelength is 850 nm, placing it in the near-infrared region, which is ideal for silicon photodetectors and is less visible to the human eye than shorter wavelengths.
• Spectral Line Half-Width (Δλ): Approximately 50 nm. This defines the spectral bandwidth, indicating the range of wavelengths emitted around the peak.
• Forward Voltage (V_F): Typically 1.6V, with a maximum of 2.0V at I_F=50mA. The low V_F is a key feature for high-efficiency, battery-operated devices.
• Reverse Current (I_R): Maximum of 100 μA at V_R=5V. This parameter is for test purposes only; the device is not intended for reverse-bias operation.
• Rise/Fall Time (T_r/T_f): 30 nanoseconds. This fast switching speed enables high-frequency pulsed operation for data transmission.
• Viewing Angle (2θ_1/2): 30 degrees. This is the full angle at which the radiant intensity drops to half of its peak value, defining the beam spread.

3. Performance Curve Analysis

The datasheet provides several characteristic curves that are crucial for circuit design and performance prediction.

3.1 Forward Current vs. Forward Voltage (I-V Curve)

This curve shows the relationship between the current flowing through the LED and the voltage across it. It is non-linear, typical of a diode. The curve allows designers to determine the necessary drive voltage for a desired operating current and to calculate power dissipation (V_F * I_F). The low knee voltage is evident from the typical V_F of 1.6V.

3.2 Relative Radiant Intensity vs. Forward Current

This graph demonstrates how the optical output power scales with input current. Generally, the radiant intensity increases linearly with current in the normal operating range. This linearity is important for analog modulation applications. Designers can use this to select an appropriate drive current to achieve a specific brightness level.

3.3 Relative Radiant Intensity vs. Ambient Temperature

This curve is critical for understanding thermal effects. The radiant intensity of an LED decreases as the junction temperature increases. This graph quantifies that derating, showing the output power relative to its value at 25°C across the operating temperature range. For reliable operation, thermal management must be considered to maintain output stability, especially in high-current or high-ambient-temperature applications.

3.4 Spectral Distribution

The spectral plot illustrates the intensity of light emitted across different wavelengths. It confirms the peak at 850 nm and the approximately 50 nm half-width. This information is vital when matching the LED with a photodetector, as the detector's responsivity varies with wavelength.

3.5 Radiation Pattern Diagram

This polar diagram visually represents the viewing angle. The pattern shows the intensity distribution, confirming the 30-degree half-angle. It helps in designing optical systems for specific coverage areas, such as ensuring a receiver is within the LED's beam.

4. Mechanical and Packaging Information

4.1 Outline Dimensions

The device conforms to a standard 5mm round LED package. Key dimensions include a body diameter of 5.0mm and a typical height of 8.6mm from the bottom of the flange to the top of the lens. The lead spacing, measured where the leads exit the package, is a standard 2.54mm (0.1 inches). Tolerances are typically ±0.25mm unless otherwise specified. A maximum resin protrusion of 1.5mm under the flange is allowed. The anode (positive lead) is typically identified by the longer lead length.

5. Soldering and Assembly Guidelines

5.1 Storage Conditions

Components should be stored in an environment below 30°C and 70% relative humidity. Once the original sealed package is opened, the components must be used within 3 months under a controlled environment of <25°C and <60% RH to prevent lead oxidation, which can affect solderability.

5.2 Cleaning

If cleaning is necessary, only alcohol-based solvents like isopropyl alcohol should be used. Harsh chemicals may damage the epoxy lens.

5.3 Lead Forming

If leads need to be bent, this must be done before soldering and at normal room temperature. The bend should be made at a point at least 3mm away from the base of the LED lens. The base of the lead frame should not be used as a fulcrum during bending to avoid stress on the internal die attach.

5.4 Soldering Process

Hand Soldering (Iron): Maximum temperature of 350°C for no more than 3 seconds per lead. The iron tip must be no closer than 2mm from the base of the epoxy lens.
Wave Soldering: Recommended profile includes a pre-heat up to 100°C for 60 seconds max, followed by a solder wave at 260°C max for 5 seconds. The dipping position must be no lower than 2mm from the base of the lens.
Critical Warning: Dipping the lens into solder must be avoided. Excessive temperature or time can cause lens deformation or catastrophic failure. Infrared (IR) reflow soldering is NOT suitable for this through-hole package type.

6. Packaging and Ordering Information

The components are packaged in anti-static bags. The standard packing configuration is 1000 pieces per bag. Eight bags are packed into an inner carton, and eight inner cartons constitute one outer shipping carton, resulting in a total of 64,000 pieces per outer carton.

7. Application Design Recommendations

7.1 Drive Circuit Design

LEDs are current-operated devices. To ensure uniform brightness and prevent current hogging, it is strongly recommended to use a series current-limiting resistor for each LED, even when multiple LEDs are connected in parallel to a voltage source. The simple circuit model (A) with a resistor in series with each LED is the correct approach. The alternative model (B), connecting multiple LEDs directly in parallel without individual resistors, is discouraged as slight variations in the forward voltage (V_F) of each LED will cause significant differences in current share and, consequently, brightness.

The value of the series resistor (R_s) can be calculated using Ohm's Law: R_s = (V_supply - V_F) / I_F, where I_F is the desired operating current (e.g., 50mA) and V_F is the typical forward voltage from the datasheet (e.g., 1.6V).

7.2 Electrostatic Discharge (ESD) Protection

This component is sensitive to electrostatic discharge. Proper ESD controls must be implemented during handling and assembly:

• Personnel should wear grounded wrist straps or anti-static gloves.
• All workstations, tools, and equipment must be properly grounded.
• Use ionizers to neutralize static charge that may accumulate on the plastic lens.
• Store and transport components in conductive or anti-static packaging.

7.3 Application Scope and Reliability

This product is intended for use in standard commercial and industrial electronic equipment, including office automation, communications, and household appliances. For applications requiring exceptional reliability where failure could risk life or health (e.g., aviation, medical life-support, transportation safety systems), specific consultation and qualification are necessary prior to design-in.

8. Technical Comparison and Differentiation

This 850nm IRED differentiates itself through its combination of high power output (30-45 mW/sr) and low forward voltage (1.6V typ.). Compared to standard visible LEDs or lower-power IREDs, this allows for brighter illumination or longer range in battery-powered devices. The 30-degree viewing angle offers a good balance between focused intensity and coverage area. The fast 30ns switching speed makes it suitable for both simple on/off remote controls and higher-speed data transmission protocols, unlike slower devices limited to basic switching.

9. Frequently Asked Questions (FAQ)

Q: Can I drive this LED directly from a 3.3V or 5V microcontroller pin?
A: No. You must always use a series current-limiting resistor. A microcontroller pin has limited current sourcing/sinking capability and lacks precise current regulation. Connecting the LED directly would likely exceed the pin's maximum current, damaging the microcontroller, and could overdrive the LED.

Q: Why is the reverse current rating only for testing, and not for operation?
A: The LED is a diode optimized for forward conduction. Applying a reverse voltage, even within the 5V maximum rating, does not cause it to function usefully. The specified reverse current is a leakage parameter used for quality testing, not a design parameter for circuit operation.

Q: How do I calculate the required resistor for a 5V supply at 50mA?
A: Using the typical V_F of 1.6V: R = (5V - 1.6V) / 0.05A = 68 Ohms. The nearest standard value is 68Ω. The power rating of the resistor should be at least P = I²R = (0.05)² * 68 = 0.17W, so a 1/4W resistor is sufficient.

Q: What is the purpose of the water-clear package if the light is invisible?
A> The water-clear epoxy is highly transparent to the 850nm infrared light, minimizing optical losses within the package itself. A colored lens would absorb some of the IR output, reducing efficiency. The clear package allows maximum radiant intensity.

10. Design and Usage Case Study

Scenario: Designing a Simple Infrared Remote Control Transmitter.
The goal is to transmit coded commands from a handheld unit to a receiver up to 10 meters away in a typical living room.

Component Selection: This 850nm IRED is an excellent choice due to its high output power (for good range), low voltage operation (compatible with small batteries like 2xAA cells providing 3V), and fast switching speed (able to handle the 38kHz carrier frequency commonly used in remote controls).

Circuit Design: The core transmitter circuit involves a microcontroller generating the modulated code. The microcontroller pin drives a transistor (e.g., a simple NPN like 2N3904) in a switch configuration. The IRED and its current-limiting resistor are placed in the collector circuit of the transistor. The transistor acts as a high-speed switch, allowing the microcontroller to pulse the LED with the required high current (e.g., 100mA pulses) without loading the MCU pin directly. The series resistor value is calculated based on the battery voltage (3V), the LED V_F (~1.6V), and the desired pulsed current.

Considerations: The wide 30-degree viewing angle of the LED ensures the remote does not need to be pointed precisely at the receiver. The ESD precautions are critical during the assembly of the handheld unit. The storage guidelines ensure the LEDs remain solderable during the production process.

11. Operational Principle

An Infrared Light Emitting Diode (IRED) is a semiconductor p-n junction device. When a forward voltage is applied, electrons from the n-type region and holes from the p-type region are injected into the junction region. When these charge carriers recombine, energy is released in the form of photons (light). The specific wavelength of the emitted light (850 nm in this case) is determined by the bandgap energy of the semiconductor material, which here is based on Gallium Arsenide (GaAs) or Aluminum Gallium Arsenide (AlGaAs) compounds. The "water clear" epoxy package encapsulates the semiconductor chip, provides mechanical protection, and acts as a lens to shape the output beam.

12. Technology Trends

Discrete infrared components continue to evolve. Trends include the development of devices with even higher power density and efficiency for longer-range applications like LiDAR and time-of-flight sensing. There is also a push towards miniaturization into surface-mount device (SMD) packages for automated assembly and smaller form factors. Furthermore, components with more tightly controlled wavelength tolerances and narrower spectral bandwidths are being developed for specialized sensing and optical communication applications to reduce interference and improve signal-to-noise ratios. The fundamental principle of electroluminescence in semiconductor junctions remains constant, but material science and packaging technology drive performance improvements.