IR Emitter
An infrared LED converts forward current into light outside the visible band. Vishay's selector guide lists emitters with different wavelengths, beam angles and output characteristics for sensing and optical tasks. The complete part number and its datasheet determine the applicable limits.
Current through the LED produces infrared radiation, and the package's optical design shapes its distribution. A sensing or communication circuit pairs the emitter with a compatible detector and drive method. Wavelength, beam angle, current, pulse duration and duty cycle must be selected together; one remote-control carrier frequency is not a rule for all infrared emitters.
In plain terms
A flashlight whose beam your eyes can't see, but a security camera or TV's IR sensor can: same physics as a visible LED, just shifted into a colour humans don't perceive.
Why designers use it
- Providing infrared illumination or an optical signal for a compatible detector.
- Optical sensing tasks such as the automotive examples in Vishay's guide.
- Selecting wavelength and beam geometry for the actual optical path.
Best for
- TV remotes
- IR illumination
- Optocouplers
Key specifications
- Operating limits: Check the exact manufacturer's datasheet (A family name does not establish voltage, current, temperature or timing limits.)
- Pin assignment: Match the complete part and package code (A similar name or function does not guarantee the same wiring.)
- Mechanical fit: Use the exact package drawing (Check pad layout, dimensions and viewing direction before building.)
When not to use it
- When ambient light, optical alignment or receiver behavior prevents reliable detection.
- When the complete emitter, optics, drive and viewing conditions have not been assessed for the applicable optical-safety requirements. A component name or reduced current alone is not a safety classification.
Common mistakes
- Confusing a pulsed-current rating with the permitted continuous current. Pulse width, duty cycle and temperature conditions matter.
- Selecting a wavelength without checking the receiver's spectral response and the optical path.
- Assuming invisible light is harmless or replacing an LED with a laser without a new safety assessment.
Where you will find it
- Vishay's automotive guide describes infrared optoelectronic components for optical sensing and related applications.
- Vishay's eye-safety note explicitly distinguishes a component assessment from the final application, particularly when arrays or additional optics are used.
A short history
Infrared LEDs apply semiconductor light emission outside the visible band. Modern emitter families support tasks such as sensing, illumination and optical communication. Their wavelength, radiant output, beam angle and pulse limits matter more than visible brightness, and an invisible beam should not be assumed harmless.