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Current rising when connect HSDIO

I have an evaluation board for AD6645. When I connected and turned on power supply, generators I begin see the digital code on output digital pins of AD6645 through oscilloscope. Then I measure current which consumes AD6645. It's OK. And then I connect to output connector J2 HSDIO PXIe-6556 and the current (net +3P3V) is rising from 80 ma to 160 mA. Has anyone encountered a similar problem (current is rising when connect to digital pins of IC HSDIO)?

 

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Hello, 

 

Can you describe in detail on what your application is and what you're trying to accomplish?  You say that you have a power supply and generator but I'm not understanding by what you're issue is.  What is the problem you're encountering?  Please be specific as possible with your set-up, application, and your issue.

 

Thanks,

Jonathan R.
Applications Engineer
National Instruments
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Here steps:

1) - connect to J4 generator SMA100A.

2) - connect to J5 generator SMA100A.

3) - connect power supply PXI-4130 to J1 to net +3P3VIN and +5V.

4) - then power on generators and power supply. AD6645 begin digitizing input analog data. Using oscilloscope i see that on connector J2 appear digital data.

5) - measure the current (through test panel) consumed by the AD6445. See that current on net +3P3VIN is about 80 mA, on net +5V - about 275 mA.

6) - connect to connector J2 HSDIO PXIe-6556. See current again: on net +3P3VIN is about 160 mA, on net +5V - about 275 mA. The current on net 3P3VIN is rising. 

 

Why current is rising when i connect HSDIO?

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Just to confirm, you're only using NI MAX to take and analyze measurements?  You may also want to take a look at how you have the instruments grounded:

 

http://www.ni.com/white-paper/3394/en/

http://www.ni.com/white-paper/3344/en/

 

Thanks,

Jonathan R.
Applications Engineer
National Instruments
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I use MAX only when see the current. I don't think that current rising is associated with grounding.

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How are you viewing this in NI MAX?  What third party devices are you using?  When you say 'connect to J4 generator SMA100A.', what is it connected to?  Please be more specific.

Jonathan R.
Applications Engineer
National Instruments
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To J4 I connect generator SMA100A. Current i see through dcpower soft test panel.

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Hello,

 

Not sure what happened with this thread.  Were you able to resolve this past issue?

 

Thanks,

Jonathan R.
Applications Engineer
National Instruments
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