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AD9833 Need +/- Vout and 50/60Hz

I'd like to generate 50 or 60 Hz with an output that swings from +2.5V to -2.5V.  I'd also like the ability to start with an exact phase (from the sinewaves zero crossing, heading negative) and the ability to stop at zero crossing.  The 9833 looks close.  If you know of a better part let me know.

Anyway, two questions:

1)  The 9833 looks like it's a 0 to 0.65V output.  Is COMP the 0.65V DAC reference?  (As in: can I buffer that voltage and us it to help with the gain and level shift action?  I need to nail zero crossing within about 1%.)

2)  Is there some issue with the part that says it won't work at 50/60Hz?  I'll be using a clock of 4MHz. Nothing seems graphed or spec'd at that low a frequency.

Thanks

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  • Hi,

    Answering your questions:

    1) No that is a pin for decoupling to ground for noise/stability reasons.The AD9834 has the reference input /  output option - however for 1% tolerance I would advice using an external reference. The ADR280 or the ADR512 are good options.

    2) Works fine at 50Hz and 60Hz.

    Setting your phase register to the desired quadrant on power up will set the waveform up correctly.

    -Liam

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  • Hi,

    Answering your questions:

    1) No that is a pin for decoupling to ground for noise/stability reasons.The AD9834 has the reference input /  output option - however for 1% tolerance I would advice using an external reference. The ADR280 or the ADR512 are good options.

    2) Works fine at 50Hz and 60Hz.

    Setting your phase register to the desired quadrant on power up will set the waveform up correctly.

    -Liam

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