I am using the DAC AD9744 in a frequency counter circuit. I send in a clock signal to initiate the data conversion. However I see a spike of the frequency of the clock signal at the DAC output. The yellow trace is the AC-coupled output signal after a buffer and there is a clear spike signal that occurs regularly.
The clock signal into the DAC is routed directly under the output traces of the DAC, so I suspect that may be pick up noise, but I am not certain whether its magnitude would be this large. The thick blue trace on the right side of the DAC is the input clock signal.
My question is: what happens to the DAC current output during conversion? Can I expect it is always in the range between output current corresponding to previous digital input and output current of the digital input that it is converting?