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DDS with phase marker?


I am designing a Howland Current Pump, and I have previously used the AD9954 and AD9833 to generate the sine waves. I was looking to use the AD9102 as it seems easier to get hold of from suppliers, and has a broader frequency range for a single clock.

However, one feature I would like to add to my design is a phase marker i.e. a pulse on another pin when zero phase is reached. Is there a DDS IC that has this feature? or is there an example circuit (like a comparator after the DAC output?) 

Thanks for any advice you can offer!


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  • Hello Jimbels,

    The datasheet assumes that you either want a sine wave or a square wave, which is the case for most users. But since you want both you can use both. Depends on how much you care about the alignment between the sine wave and the square wave, you might not want to use two separate filters, especially if the two filters have different transfer functions, which looks like the case in the datasheet. You can potentially just have one differential filter between the transformer and IOUT/IOUTB, and feed the comparator from the output of the filter is kick back is acceptable.