AD2S1205 startup issue

Hello, I'm testing a new design with a AD2S1205 resolver decoder. I have my design assembled, and applied 5v to the Vdd. I have been using a 100 ohm resistor to pull down the reset signal by hand, and when I remove it I observe the current draw by the 5v rail to go from <10mA to >10mA, so I believe that to be working. In addition, I see the voltage at EXC and !EXC as well as the clock input go from 0v to ~2.5v. However, I can't seem to find any other indication that the AD2S1205 is operational. I assume that the complimentary EXC signals should be generating a 10khz signal, and that the IC should be trying to oscillate the 8.192mhz crystal, but neither seems to be the case.

I suspected that the IC was damaged, and replaced it with a new one, but the new one behaves the same way.

What behavior should I look for to indicate that the device works? What do I need to do to get the IC to excite the resolver coils?

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  • 0
    •  Analog Employees 
    on Dec 21, 2019 6:25 PM

    Jackson,

    Can you tell me a little bit more about your application in terms of how you've connected the 1205 to the resolver?

    Please note that Analog Devices offices will be closed from 12/23/2019-01/06/2020 and thus responses may be delayed.   Our apologies in advance for any inconvenience.

    Happy Holidays

    Sean

Reply
  • 0
    •  Analog Employees 
    on Dec 21, 2019 6:25 PM

    Jackson,

    Can you tell me a little bit more about your application in terms of how you've connected the 1205 to the resolver?

    Please note that Analog Devices offices will be closed from 12/23/2019-01/06/2020 and thus responses may be delayed.   Our apologies in advance for any inconvenience.

    Happy Holidays

    Sean

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