hello
I need a 38 kHz square-wave generator (for an IR LED), but it needs to generate the 38 kHz square-wave for 1ms, and stop generating (LOW) for 1ms

I can't use too many components/routes (the single layer board must have at most 16mm/0.6inches width)

I guess a microcontroller would probably be a good idea, but is it possible to do that with a few resistors/capacitors using a 556 as schmitt trigger (or even a 74c14/similar)?

thanks

 

I guess you could use a 556, and the reset pin on the 38 HHz osc to gate the signal

 

I guess you could use a 556, and the reset pin on the 38 HHz osc to gate the signal

yes, but I guess I'd need enough components that wouldn't fit on a 0.6inches single-layer board

for instance, I tried to do that:

(got it from http://forum.allaboutcircuits.com/showthread.php?t=26272&page=2 ), and it gets wider than 1 inche

 

I guess then a 8 or 6 pin micro would be the best. Many of them come with internal osc. So you will only need the chip and a 100nF decoupling cap.

 

This code is for a PIC10F202, should be easy enough to modify.
It's an 8 pin DIP or 6 pin SOT-23 package (3.2 X 3.1mm)
http://forum.allaboutcircuits.com/showpost.php?p=258763&postcount=10