AOUT module calibration

[pelek]

Hello.

I'm testing AOUT module, and I don't have the same voltages on all 8 channels.

I'm using for 10k Rx resitor, precision ones with 0.1% tolerance (and I picked by hand the same values from a lot).

But even with the same resistors, one chanell gives me 1.0v-2.1v-4.2v-8.4v, one 1.1v-2.3v-4.6v-8.8v, one 1.0v-1.98v-3.8v-7.8v etc.

Any suggestions ?

 

I should test many TL074's until I find the right ones ?

 

 

Thank you.

[latigid on]

I suppose you mean an AOUT with MAX525? What app are you testing with? The SEQ has a calibration part too.

But first, have you adjusted the trim pots to give a good scaling factor? The DAC with external reference outputs a voltage between 0-2.048V with graduations of 1/4096. The gain equation is also on the page.