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NI5640R generating output signal after PC boot

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NI5640R generating output signal after PC boot

I noticed the NI5640R always generates a signal on AO1 after I boot my PC (before running labview) or when the PC wake-up after sleep without labview running.

I guess it is because the FPGA is automatically loading a design doing that.

However, this output is not the design I use. It disappear as soon as I start the VI loading the FPGA with my design.

This wrong output is much more powerful (-3dBm) and damaged the board it was plugged to.

 

How could I get rid of it?

 

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Accepted by topic author nonoriri
06-23-2016 12:19 AM

Re : NI5640R generating output signal after PC boot

Hi Nonoriri,

No, unfortunately, there is no way to delete the initializing noise on the 5640R.

Regards,

 

Jovan N. - Application Engineering
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Re : NI5640R generating output signal after PC boot

This is bad news.

AO1 is wired to the input of  a RF power amplifier.

Such power amplifier should not be powered-off if there's input signal (risk of damage), so I'm supposed to leave it powered.

But the input signal coming from NI5640R noise is way too high so after amplification, the component at the output will damaged.

 

I don't see a good way (=hardware friendly) to manage this except diconnecting SMA1 of AO1 before every PC boot to reconnect it once labviewhas started and loaded the FPGA.

 

Is it what people do?

 

 

 

 

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