I have used the TSOP1738 and TSOP1838. These were originally from TEMEC but now Vishay. Look at this past post for links to the data sheets. Previous IR Receiver Discussion. I have found these parts to out perform IR receivers from SHARP and EVERLITE. I have not evaluated the Infineon parts.

The pulses you are seeing on the output are most likely caused by florescent lights. For some reason there are light spikes emitted by these lights that can casue this effect. The best overall fix I have found to help against this is to make sure you have an IR window in front of the receiver part. The color of the window should be selected so that it attenuates light frequencies on either side of the IR transmitter LED center frequency say at 840 or 970 nm or what ever. Very dark purple windows are best. My testing has shown that the colored plastic of IR detectors themselves is too close to the IR receiver to be as effective as an additional window. If you want to test a window get your hands on an old TV remote with such a window on the transmitter and take it off the case and then tape it in place over your IR receiver. I use black plastic electrical tape for this purpose.

There is also a cool and simple test you can do to see if the receiver is responding to stray light in the room. Get yourself a black plastic anti-static bag (The type vendors sometimes bundle PC boards or IC tubes in). Cut a piece of this plastic about 400 mm by 400 mm. Roll this up into a sort of tube that is about 18->20 mm in diameter and tape to retain the roll. Then tape this in place directly in front of the IR detector. Then point your tube away from most light sources and aim remote transmitter right at the receiver via the tube to test for normal transmissions. When you are not transmitting you can see if the receiver output is quiet. If so then the glitches you are seeing are caused by stray light.

Another consideration is that if you tried to build a full duplex inteface using an IR LED and a IR detector on each end then you would most likely need to separate the IR LED from the detector on the same end with some type of IR Opaque barrier.

Michael Karas