SMD Infrared LED
July 3, 2026
Read：10
Source: lideda
What Is an SMD Infrared LED?
An SMD (Surface Mount Device) infrared LED is a semiconductor light source that emits infrared (IR) light, which is invisible to the human eye. Unlike visible LEDs that produce white, red, or blue light, infrared LEDs emit wavelengths typically ranging from 700 nm to 1050 nm, with 850 nm and 940 nm being the most common.
SMD infrared LEDs are mounted directly onto printed circuit boards (PCBs), making them ideal for compact, automated manufacturing and high-volume applications.
How Does an SMD Infrared LED Work?
An infrared LED converts electrical energy into infrared radiation through electroluminescence.
The process is simple:
Current flows through the semiconductor junction.
Electrons recombine with holes.
Energy is released as infrared photons.
The emitted infrared light is detected by cameras, sensors, or receivers instead of the human eye.
Unlike laser diodes, infrared LEDs emit light over a wider angle, making them suitable for illumination rather than focused beams.
Common SMD Infrared LED Packages
| Package | Power | Typical Wavelength | Applications |
|---|---|---|---|
| 2835 | 0.2–0.5 W | 850nm / 940nm | Sensors, smart home |
| 3030 | 1 W | 850nm / 940nm | CCTV cameras |
| 3535 | 1–3 W | 730–940nm | Machine vision, security |
| 5050 | 1–3 W | Multi-chip IR | Industrial lighting |
| High-Power SMD | 3–10 W | 730–1050nm | Medical and industrial systems |
Common Infrared Wavelengths
| Wavelength | Visibility | Typical Applications |
|---|---|---|
| 730 nm | Deep red visible | Plant lighting |
| 780 nm | Very faint red | Optical devices |
| 810 nm | Nearly invisible | Medical therapy |
| 850 nm | Slight red glow | CCTV, night vision |
| 880 nm | Invisible | Optical sensors |
| 940 nm | Completely invisible | Face recognition, IR remote controls |
| 1050 nm | Invisible | Industrial detection |
850nm vs 940nm Infrared LEDs
| Feature | 850nm | 940nm |
|---|---|---|
| Brightness to camera | Higher | Lower |
| Visible red glow | Slight | None |
| Night vision distance | Longer | Shorter |
| Human visibility | Slightly visible | Invisible |
| Security applications | Excellent | Excellent for covert surveillance |
850nm LEDs provide stronger illumination and longer detection distances, making them ideal for surveillance cameras.
940nm LEDs produce no visible glow, making them the preferred choice for hidden cameras, biometric devices, and covert security systems.
Advantages of SMD Infrared LEDs
Compact Design
Surface-mount packaging enables smaller products and higher PCB density.
High Reliability
SMD LEDs offer long operational lifetimes, typically exceeding 50,000 hours under proper thermal management.
Energy Efficiency
Infrared LEDs consume less power than traditional incandescent IR sources while providing stable output.
Fast Response Time
Switching speeds are measured in nanoseconds, making them suitable for communication and sensing applications.
Easy Automated Assembly
Compatible with SMT production lines for cost-effective mass manufacturing.
Typical Applications
SMD infrared LEDs are widely used in many industries:
Security cameras for night vision illumination
Face recognition systems using 940nm IR
Machine vision and industrial inspection
Remote controls for TVs and consumer electronics
Optical sensors and proximity detection
Automotive driver monitoring systems
Medical therapy equipment
Smart home sensors
Robotics and automation
Biometric authentication devices
Key Specifications to Consider
When selecting an SMD infrared LED, engineers typically evaluate:
Wavelength: 730–1050 nm
Forward Voltage: 1.2–2.0 V
Forward Current: 20–1000 mA
Radiant Power: Depends on package and drive current
Viewing Angle: 20°–140°
Package Size: 2835, 3030, 3535, 5050
Operating Temperature: −40°C to +85°C (or higher for industrial models)
Choosing the Right SMD Infrared LED
Different applications require different combinations of wavelength, power, and beam angle.
| Application | Recommended Package | Wavelength |
|---|---|---|
| CCTV Cameras | 3030 / 3535 | 850nm |
| Hidden Surveillance | 3535 | 940nm |
| Face Recognition | 3535 | 940nm |
| Remote Controls | 2835 | 940nm |
| Industrial Vision | High-Power 3535 | 850nm |
| Medical Devices | High-Power SMD | 810nm / 850nm |
| Optical Sensors | 2835 | 850nm or 940nm |
SMD infrared LEDs are a compact, efficient, and highly reliable solution for applications requiring invisible illumination. Available in packages such as 2835, 3030, 3535, and 5050, they support wavelengths from 730 nm to 1050 nm, with 850 nm and 940 nm dominating security, sensing, and biometric markets.
When selecting an SMD infrared LED, consider the required wavelength, optical output, package size, viewing angle, and thermal performance. Choosing the right combination ensures optimal efficiency, long service life, and reliable performance in applications ranging from night vision cameras to industrial automation and medical devices.
Table of Contents
