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I want to learn how to demodulate a 38 kHz IR PWM signal.(Such as that transmitted by a TV Remote Control) I know it can be demodulated easily using a TSOP1738 IR receiver.

I realize that the TSOP1738 can be much more easily implemented, but how is the signal demodulated inside the reciever ?( I am not planning to build a demodulator, just curious how it works).

I searched online but couldn't find the mechanism anywhere. I looked at the datasheet and the block diagram just shows a demodulator but not how it works.

(I have attached the block diagram in case it helps)TSOP1838_Block_Diagram

Edit : Typo in the title

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    \$\begingroup\$ I think it is just an amplitude demodulator. Maybe just an envelope detector. \$\endgroup\$ – mkeith Mar 23 at 21:04
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    \$\begingroup\$ Datasheet for TSOP1738 identifies it as a "Heimdall" IC, and a Google search for "Vishay Heimdall" leads to you their document Circuit Description of the IR Receiver Modules which appears to provide a full description. \$\endgroup\$ – Mr. Snrub Mar 23 at 21:12
  • \$\begingroup\$ The link listed by "Mr. Snrub" provides good information, and you have stated you are not interested in creating a receiver of your own. You only wish to know more about them. I have found that working with IR signals and using an IR receiver has helped me to understand them VERY well. This link is a multi-part article about IR, and is done very well... learn.adafruit.com/ir-sensor/overview \$\endgroup\$ – Wendall May 15 at 21:34

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