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[M8190A] DAC value range to output voltage

Question asked by wobbert on Apr 3, 2018
Latest reply on May 16, 2018 by thysell

Hi folks,

 

I am trying to send my own waveforms to the M8190A via VISA/matlab. The programming guide states that:

DAC values have 14 bit resolution in precision mode and 12 bit in speed mode. DAC values are signed. Valid range is -8192 to +8191 in precision mode and -2048 to 2047 in speed mode.

However it does not state how these DAC value ranges are mapped to output voltages. Because the DAC value range is not symmetrical, I assume that that -1 will correspondent to -0.5*LSB V and that 0 will correspondent to 0.5*LSB V. Is this correct? If not, could you tell me what the exact mapping is? (Note: I would like to measure this myself, but we don't have the equipment in our lab to do so).

 

Second question: I noticed that if you send a sine wave to the AWG using the full ADC value range (thus -8192 to +8191) and I change the amplitude of the AWG via the VISA command ":VOLT<1|2>:AMPL <level>", the amplitude of the output voltage still changes (which I did not expect to happen). Does this mean that the minimum step size of the AWG output scales with the given output amplitude (thus that the Dynamic Range is constant even if the output amplitude changes)? And how does this affect the performance of the machine? Does, for example, the ENOB changes over output amplitude?

 

I am eager to learn more about this awesome machine

 

Kind regards!

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