XR2211 Fsk Demodulator

[muhammadumair]

Hi, I am using XR2211 for BFSK demodulation at 1200bps. My mark and space frequencies are 1800 Hz and 2600 Hz. Problem is that I am having a number of unnecessary transitions between two bits. These transitions increases so much that at higher baud rates my output bit is ignored by the FPGA next to it and it captures these transitions instead of output. How can I remove these unnecessary transitions between bits? or at least reduce them to capture my desired output?...can anyone help me?

 

[guitargore]

I found when I used that chip that the DO signal gets very noisy, which is what I believe you are describing, when the analog input voltage is very low (< 100mV).