s2-lp narrowband

[Mmila.9]

Hi

do i need an external txco for narrowband operation?

regards

[BKess]

Hi Marco,

I am not an ST expert.

But as far as I know you do not necessarily require a tcxo. You may also use a crystal as long as the frequency stability is good enough (maybe +/-10ppm, depending on your datarate and bandwidth).

Remember "frequency accuracy" and "frequency stability" is not the same. Frequency accuracy only applies to 25°C, whereas frequency stability applies to the whole temperature range.

regards

Beat

[Winfred LU]

I second this. A TCXO is not required.

Please refer to ST evaluation boards. I think all the boards are using crystals.

Best Regards,

Winfred

[Mmila.9]

hi

boards uses crystals .+-10ppm

of coarse i need for narrowband both

the question is that cc1125 uses tcxo for narrowband ,crystall for larher band. i immagine is the same fors2-lp or not ?

[Winfred LU]

Hi Marco Milazzo,

It is fine to use this crystal, since a crystal with +-10ppm is better than requirement for S2-LP.

If you would like to use a TCXO, it will also work properly.

Take Sigfox application (ultra narrow band) for example, for some zone with higher frequency offset requirement, we may still get S2-LPs certified with crystals.

But some of our customers also choose to use TCXOs for better frequency stability in order to save time tuning the board.

Thank you.

Best Regards,

Winfred