TIDA-060001: Can this design achieve Fm 850KHz FSK?

Hello PYTsai,

The AFE031 transmitter and receiver signal paths PGAs, PAs, etc. have enough bandwidth in certain gains to support an 850 kHz FSK signal. But the internal CENELEC transmit and receive low-pass filters would not be usable because their cutoff frequencies are well below 850 kHz. External 850 kHz low-pass filters would have to be employed instead of the internal filters.

A second concern was the DAC speed, but it turns out that it is rated for a 1 MHz conversion rate. It should be usable at 850 kHz. Since it is followed by the TX PGA and then normally by the transmit low-pass filter, the same issue with the filter cutoff frequency arises.

There may be some other issues we didn't consider that would become evident once more in-depth thought is given to this application.

Do note that no development efforts have been made by TI to run the AFE031 in FSK, at 850 kHz. Development of this unique AFE031 application and mode would have to be undertaken by those interested in using the product in that manner.

Regards, Thomas
Precision Amplifiers Applications Engineering