DAC39J84EVM: External clock

Weiyu Leng

Part Number: DAC39J84EVM
Other Parts Discussed in Thread: DAC39J84, LMK04828

To whom it may concern:

We own a DAC39J84 EVM and we have successfully synchronized the DAC with KC705 FPGA without the interposer.

Currently, the FPGA was driven by a clock fed from DAC board's PLL at 368.64MHz.

I wonder how can the system be reconfigured minimally if I want to use an external clock of integer frequency (160MHz 320MHz etc)

Thank you

Best,

Weiyu Leng

over 6 years ago

0 jim s over 6 years ago

TI__Guru* 91947 points

Weiyu,

Setup the GUI as shown in the attachment and provide the external clock source to SMA J17. Use about 10db of power for this input. This example is for 300MHz with no interpolation. If you plan on using interpolation, the external clock is the rate shown by the DAC Output rate in the GUI.

Regards,

Jim

DAC39J84_Ext_Clk.pptx

0 Weiyu Leng over 6 years ago in reply to jim s

Intellectual 360 points

Hi Jim,

Will the external clock at SMA J17 be routed to FPGA through the FMC connector, so that the FPGA and DAC can be synchronized?

Thank you

Weiyu Leng

0 jim s over 6 years ago in reply to Weiyu Leng

TI__Guru* 91947 points

Weiyu,

Yes. This external clock goes to the on-board LMK04828 and the outputs from this part get routed to the FMC for the FPGA board and the DAC. The LMK generates the device clock which goes to pins D4/D5 on the FMC connector and SYSREF which goes to pins G9/G10.

Regards,

Jim

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DAC39J84EVM: External clock