Hi every body,

I have some problem to generate an output on ad9914 controlled through FPGA. In fact after configured the internal control register CFR, and write value of FTW,AMP and POW in profile 0, i do not have the same value in output.

For example: i write 0x0A101250 in FTW ; 0x402 in AMP and 0x1250 in POW to generate 98.26Mhz

At the output i have 271,41Mhz

I don't understand why?

Even when i change the frequency, the output change also not the same frequency .

I hope someone can help me

Best regards

Hi kemoah,

Using the formula fout = FTW/(2^32) * fsysclk. Assuming that you are using a 3.5 GHz clk, fout would be 137.5 MHz. Are you using a different clk frequency for the formula or not? I'm also suspecting that you have overlapped the register address on both FTW register and POW& register. kindly check if this wasn't the case.

Best Regards

Louijie