AD9154-FMC-EBZ -> J1 clock requirements

Hi madhu90 ,

Thanks for using AD9154.

Regarding your queries, please see below.

The J1 SMA connector on the AD9154-FMC-EBZ evaluation board is used to provide an external clock input to the onboard AD9516 clock distribution chip.  This clock is used internally to generate the DAC clock (DACCLK), SYSREF, and other timing signals required for JESD204B operation.  The AD9516 outputs a differential clock signal that is routed directly to the CLK+ and CLK– inputs of the AD9154 DAC.  This differential clock is what actually drives the DAC sampling process.

madhu90 said:

Is this RF Generator?

Yes, the signal source required for J1 is an RF signal generator.  It must have a clean sine wave at 1.5 GHz that can provide +3 dBm power level.  And have low phase noise to ensure signal integrity for high-speed DAC operation.

madhu90 said:

Can I use Keysight Signal Generator?

Absolutely. Keysight RF signal generators (e.g., MXG, EXG, PSG series) are well-suited for this application. Just ensure the model you choose supports 1.5 GHz output and can be configured to +3 dBm.

madhu90 said:

Is 1.5GHz same regardless of the DAC sampling rate? => I want to have 1GSPS DAC sampling rate.

No, the 1.5 GHz clock input is not strictly required for all DAC sampling rates on the AD9154. You can operate the DAC at 1 GSPS, but the external clock frequency (fed into J1) must be chosen carefully based on how the onboard AD9516 clock distribution chip and the AD9154 PLLs are configured.  The 1.5 GHz clock is a recommended default for evaluation setups.  You can use a different frequency at J1 as long as, the AD9516 is configured to generate 1GHz DACCLK from it.  The resulting clock meets jitter and phase noise requirements for high-speed DAC operation.  You could input 1 GHz directly and configure AD9516 to pass it through or input 2 GHz and divide it by 2 to get 1 GHz.

madhu90 said:

Also, please let me know the electrical interface between RF generator & J1 of Eval board.

J1 is an SMA female connector.  You can use a 50-ohm SMA male-to-male coaxial cable.  Ensure the RF generator output is 50 ohms to match the board input.

Thanks and kind regards,

Alex

Hi AlexAtienza  

Thank you for your reply

• Please let me know which RF Generator is used in the demo / Quick Starter Guide
  • EVALUATING THE AD9154 DIGITAL-TO-ANALOG CONVERTER [Analog Devices Wiki]
• I found EVAL-ADF4351 Sample & Buy | Analog Devices. Can I use this to generate 1.5GHz sine wave?
  • This EVAL-ADF4351 has RFOUTA+ & RFOUTA- (differential pair). I plan to use output RFOUTA+ to connect to J1 (this is single ended, right?) and terminate RFOUTA- with 50 Ohm
• I am looking for cost effective solution

Thanks a lot again

Madhu

Hi AlexAtienza 

Please reply. I think once I get clarity on this, I can proceed with the setup.

Thanks

Madhu

Hi madhu90 ,

Apology for the late response. 

Please see below:

madhu90 said:

Please let me know which RF Generator is used in the demo / Quick Starter Guide

• We are currently utilizing Rohde & Schwarz signal generators, specifically the SMA100A or SMA100B models.

madhu90 said:

I found EVAL-ADF4351 Sample & Buy | Analog Devices. Can I use this to generate 1.5GHz sine wave?

• The EVAL-ADF4351 is a viable alternative, offering a frequency range from 35 MHz to 4.4 GHz. It provides adjustable output power between –4 dBm and +5 dBm and features differential RF outputs via RFOUTA+ and RFOUTA– SMA connectors. The device can be controlled through a USB interface using GUI software or via a microcontroller.
• You may also seek assistance or recommendations on the RF & Microwave forum to determine whether the EVAL-ADF4351 is a suitable cost-effective solution, or if there are other components that better meet the requirements of the AD9154-FMC-EBZ.

madhu90 said:

This EVAL-ADF4351 has RFOUTA+ & RFOUTA- (differential pair). I plan to use output RFOUTA+ to connect to J1 (this is single ended, right?) and terminate RFOUTA- with 50 Ohm

• You can use RFOUTA+ as a single-ended output to drive the J1 input of the AD9154-FMC-EBZ by connecting RFOUTA+ to J1 with a 50-ohm SMA cable. To maintain impedance balance and prevent signal reflections, RFOUTA– should be terminated with 50 ohms to ground.

When setting up the system, consider using a low-loss SMA cable to minimize signal degradation. Ensure that the phase noise performance is suitable for JESD204B clocking. If spurious tones are a concern, adding a bandpass filter may help improve signal purity.

Thanks and kind regards,

Alex

Hi AlexAtienza 

Thank you for your reply.

Madhu