IR modulation tolerance?

Other Hardware Sensors
1

Hi all,

Was helping on an other thread and it got me wondering what tolerance there is on IR modulation?

38kHz seems a common standard (de facto, if not de jure), but presumably there's some tolerance and one could maybe get away with (say) 37.9 to 38.1 or something?

TIA,

Jim

(... who by the way is bored shitless waiting for paperwork for my new contract which starts soon.)

2

It looks like for this family of modules the -3db (50% sensitivity) point in the carrier filter is at f0 +/- 10%. That means a 38 kHz receiver will be half as sensitive at 34.2 or 41.8 kHz. Since almost all remotes use 36 to 40 kHz you can cover almost all remotes with a 38 kHz receiver.

3

Thanks, John.