Vishay OPTO Squad

AGC6 for Smartphone IR Proximity Interference

Vishay is the world’s leading supplier of IR receivers for remote control and presence sensing.  We offer the most sensitive receivers which translates to the longest transmission range and we offer the best optical noise suppression which ensures signal reception.

Our receivers must suppress optical noise generated by multiple sources of ambient lighting from compact fluorescent lights to plasma TV emissions.  There is a relatively new source of infrared noise that our receivers are now able to suppress.  Your smartphone has a feature that turns off the display when you bring the phone to your ear.  This feature is enabled by using a reflective sensor which emits either a modulated pulse or single pulses of infrared light and, when receiving a reflected signal, notifies the controller to shut down the display.

The interference patterns emitted by popular smart phones were reproduced in the lab and our IR receivers were exposed to them in a controlled environment. The test evaluated the shortest distance between the IR receiver and the interference source without producing spurious output pulses.

A comparison of AGC4 (orange) and AGC6 (blue) settings clearly demonstrates the enhanced performance of AGC6 for most of the signal patterns.  Ideally, you could bring the smart phone directly next to the IR receiver and not receive spurious pulses.  Where the blue column is barely present, that is just the case.  Consider AGC6 if your design could be influenced by the presence of smart phones.  One thing to remember, the proximity sensor of the smart phone is only emitting infrared pulses when making a call.

For complete details, please read the application note found at:

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This entry was posted on November 30, 2018 by in Articles.
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