I want to generate waveforms with small amplitude relative to the DC offset, e.g. a square wave going between 1.0 and 1.01V. The regular DC offset field is limited to twice the waveform amplitude. But the real problem is the way the 33120 scales output by the peak-to-peak range of the arbitrary waveform data. The output appears to be:
volts = amplitude * DN / (MaxDN - MinDN) + offset
For my example 1.0 to 1.01V, the best I can do is
amplitude = 0.01
offset = 0.02
MaxDN = 2047
MinDN = 2026
Then the actual output is 0.985 to 0.995 V. :(
I know about adding an external DC supply to offset the output, but is there some way to bypass the peak-to-peak range scaling? In the above example, if I create a waveform from 0.0 to 1.01V, using
amplitude = 1.01
offset = 0.505
MaxDN = 2047 (output is 1.01V)
MinDN = -2047 (output is 0V)
and DN = 2006 for output = 1.00V
There's plenty of resolution - but adding the point at -2047 will cause a glitch in the output.
Thanks for any ideas.
volts = amplitude * DN / (MaxDN - MinDN) + offset
For my example 1.0 to 1.01V, the best I can do is
amplitude = 0.01
offset = 0.02
MaxDN = 2047
MinDN = 2026
Then the actual output is 0.985 to 0.995 V. :(
I know about adding an external DC supply to offset the output, but is there some way to bypass the peak-to-peak range scaling? In the above example, if I create a waveform from 0.0 to 1.01V, using
amplitude = 1.01
offset = 0.505
MaxDN = 2047 (output is 1.01V)
MinDN = -2047 (output is 0V)
and DN = 2006 for output = 1.00V
There's plenty of resolution - but adding the point at -2047 will cause a glitch in the output.
Thanks for any ideas.
I can't imagine why the thing has to scale by MaxDN - MinDN (instead of always scaling by 4094), it sure causes problems.
BTW: by "DN" I'm referring the the "DAC" values.