IR Receiver
Receives a 38 kHz (or 36/40/56 kHz) carrier-modulated IR signal at 940 nm, automatically gains, bandpasses, and demodulates the carrier, and outputs a clean active-low logic signal for the remote-control protocol decoder.
An on-chip PIN photodiode converts incident 940 nm light into photocurrent. An automatic-gain-control amplifier holds output amplitude steady across decades of incident illumination. A 38 kHz bandpass filter rejects ambient IR (sunlight, incandescent lamp flicker at 100/120 Hz harmonics, fluorescent ballast harmonics). A peak detector and Schmitt comparator output a clean digital pulse for each modulation burst. Most parts include a stop-current limiter to suppress continuous-wave 'jamming' from CFL lamps.
In plain terms
Like a radio receiver tuned to one station — bright sunlight is the static of every other channel, and the chip filters everything except the precise 38 kHz beep its remote sends.
Why designers use it
- Universal IR remotes — every TV, set-top box, AC, and projector shipped since the 1980s expects this exact silicon.
- Ambient-light immune — the AGC and bandpass keep performance constant from a dark theatre to a sunlit room.
- Single-chip simplicity — three pins (VCC, GND, OUT), a 0.1 µF cap, and a series resistor are the entire BOM.
- Cheap — a Vishay TSOP38238 sells for cents in volume, and pin-compatible alternatives ship from a dozen makers.
Best for
- Remotes
- Smart-home hubs
- Industrial IR data
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
- Where the carrier is custom or out-of-band — pull a discrete photodiode and a TIA front-end.
- When data rates exceed ~3 kbit/s effective — IR receiver modules aren't designed for streaming; reach for IrDA or proper optical link ICs.
Common mistakes
- Pairing a 38 kHz receiver with a 36 kHz remote — the bandpass attenuates the carrier and the range collapses to 30 cm.
- Skipping the 47 µF / 0.1 µF supply decoupling combo — switching noise from a nearby SMPS modulates the AGC threshold and the demodulator outputs phantom pulses.
Where you will find it
- A Logitech Harmony Elite universal remote and its associated Hub each include a Vishay TSOP38238 38 kHz IR receiver: the chip's daylight rejection and AGC let users press the remote from anywhere in a sunlit living room and still control 15 devices clean across the IRDA chip's data band.
- A Mitsubishi Electric MSZ-FH09NA mini-split air-conditioner head's IR window houses a Sharp GP1UE271RK 38 kHz IR module: the chip's 18 m receiver range (with a strong remote) lets occupants change temperature from across an open-plan loft.
- A Roku Express media player's front IR receiver (a Vishay TSSP58P38) handles the 38 kHz remote's NEC protocol bursts: the on-chip carrier filter rejects the 100 Hz fluorescent fixtures common in budget hotels, where competing brands' players intermittently lose remote response.
A short history
A remote-control IR receiver detects modulated infrared light and converts it into an electrical output. A photodetector, amplifier and demodulation circuitry recover the transmitted pattern while filtering interference. The supported carrier frequency and coding conditions depend on the receiver, so one module is not necessarily compatible with every remote.