ir sensor

hey i want to build an Ir receiver which normally uses tsop1738 sensor but it is not available in our area and tsop1138 is available. Is there any prblm in replacing 1738 with 1138.

One really have to look at the datasheets in order to answer your question.

They have same IR frequency, pinouts, voltage rating and output polarity and differs only in data rates so either will be good for your application, which I assume will be IR remote control signals, right?

The TSOP1138 is NOT suitable for continuous IR signals data transmission so ultimately selection depends on your application.