DAC38RF85: Problem generate single tone

Eugene,

The constant value is shared by both DUC's in the DAC38RF85. Any change here will affect both the same. To have different amplitudes, use the GAIN AB and GAIN CD registers. I have attached an example configuration file that creates a 100MHz and 200 MHZ tone from the CHA output at two different amplitudes. The DAC PLL was set to 6000MHz using a 100MHz reference clock. The GUI settings that were used are also attached. No JESD204 interface was used.

Regards,

Jim

DAC38RF85_NCO_100M_200M_ref_422.pptxDAC38RF85_LMF_442_NCO_AB_100MHz_NCO_CD_200MHz.cfg

Hello Jim.

Thanks for the quick response.

I can not use GUI in my board. But i load registers from attached cfg file to FPGA.

PLL_LFVOLT and TEMPDATA are not read correctly with them. 

I guess I made a mistake with the settings, but I can not find the error. I double-checked everything several times.

Here are my settings that PLL works with. But with them I get a negative ofset voltage in output. 

Then i deerease SPIDAC to 0, and DACFS to 0, i see 100 mv frequency ~50 MHz in output, and negative ofset 500 mv.

I use 125 MHz reference clock. PLL_N = 1 PLL_M = 18. 

NCO frequency - 62.5 MHz.

0x01 0x3000

0x40b 0x0002
0x431 0x0400
0x432 0x110f
0x433 0xc038

0x10C 0x2620
0x119 0x0001
0x11E 0xc71c
0x11F 0x1c71
0x120 0x017c
0x127 0x8888
0x12F 0x0001
0x128 0x0882
0x128 0x0880
0x130 0x0000

I found a problem. In the board installed TCM2-43X+ transformer, instead TCM3-452X-1+.

Are you running now or still need help?

Can I use TCM4-452X+ instead TCM3-452X-1+?

Thanks.