Analog Discovery 2 AWG output current

[albertd200]

Hello, 

My question is about the output current of the AD2, AWG. I know the current Max. Output is 10mA, but, I can't find if that current is expressed in Irms or it is Ipeak. 

I need to know that, because I want to build a box with a potentiometer inside, in order to control the output amplitude in an analogic fashion, setting the AWG out (sinewave) to 10Vpp (5Vp or 3.53Vrms) and set the potentiometer to taste to achieve the voltage needed. 

Trying to figure out what potentiometer I should use, doing the math tells me that a 50ohm pot is way too low to load the AWG output, taking the 50ohm output impedance from the BNC board and adding the 50ohm potentiometer, it gives 50ohm + 50ohm = 100ohm then 5Vp/100ohm = 50mA ... five times the Max Rated current of the AWG output if the 10mA is expressed in peak current, or 50mA x 0.707 = 35.35mA thre and a half times if it is expressed in rms current. 

So, doing the inverse math, with a maximum current of 10mA, and the maximum voltage coming out of the AWG, it gives :

5Vp / 10mA = 500ohm potentiometer or 3.53Vrms / 10mA = 353ohm (not a standard value). 

Could I use a 500ohm potentiometer safely to control the amplitude of the AWG output with no drop of the 5Vp? 

If I'm  at the maximum output voltage and current, will it present more THD at this output?

Thanks in advance

Albert  

 

   

[attila]

Hi @albertd200

The max output current depends on the voltage level and it is at least 10mA (peak). 
For more details see: https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/reference-manual#awg_out

[albertd200]

Thanks for your answer, but.

As I said in my previous post, I would use the maximum output from the AWG that is 5Vp or 10Vpp ... Could I use the potentiometer or not in that case? The link provided doesn't answer my question. 

Thanks in advance. 

Albert