ALtera AD/DA questions

[jdh_1984]

Hi
I don't know which forum to post this thread, but I tries this one.
I thinking of bying this AD/DA converter :Terasic - Daughter Cards - AD/DA - Highspeed AD/DA Card
But in the datasheet it is written that it doesn't support DC signaling, what does this mean? I am going to read a accelerometer value (0-5V), I see the input range is 2V p-p, could I use this with a scaling circuit (opamp => scale the signal 2V p-p) to read my accelerometer value?

 

[steve.hunch]

If your ADC does not support DC signaling, this can be a problem, it depends, how fast your signal at the output of accelerometer is changing. It might be that you will read zero at the end, because of the ac coupling of ADC.

 

[Jack// ani]

Did you also read data sheet of ADC used on this board?

I believe they must have placed a bypass capacitor at ADC input to get rid of DC level. Yes, you can use opamp for scaling the accelerometer to desired 2V p-p.

 

[FvM]

The daughterboard has in fact a low-pass cut-off around several 100 kHz and isn't suited for measuremnets like you intend.

I believe they must have placed a bypass capacitor at ADC input to get rid of DC level.

It has input transformers and can't be easily modified for DC capable measurements.

To correct the above statement, it's actually a high pass, so it can't transmit DC.

 

[Jack// ani]

The daughterboard has in fact a low-pass cut-off around several 100 kHz and isn't suited for measuremnets like you intend.


It has input transformers and can't be easily modified for DC capable measurements.

Ahh...I see, thanks for informing us.

 

[jdh_1984]

Tnx for useful information.

Anyone that have a ADC (evaluation board) to recommend? 10Bit or more with parallel interface. I am going to use it to read from a accelerometer and gyro in this project, but in the future it could be used in project which require faster readings.