Hi ADIexpert
I would like to use the refout1 of ADUM4190 as a voltage reference to my other circuits in the schematic
I connected the REfout1 to the non invert pin of a TL074 to build a voltage follower without attaching any loading on the output of TL074 .
however , the ADUM4190 is damaged after I did this
may I know if this application is ok for ADUM4190?
I don't understand what went wrong if I did this, there is not a lot of description on REFOUT in the datasheet except capacitance limitation ?
thanks
Ken
Hi Ken:
ADuM4190's REFOUT can not source too much current (10's of uA) but considering TL074's input resistance is very high. This application is OK.
Have you ever capture the waveform on REFOUT1 when this damage appear?
Regards
Chris
Hi Chris
yes, please see the picture below
as you can see from the green waveform, the refout1 steadily output 1.225V in the first place and after the while the waveform was distorted.
in this measurement, I didn't even connect the refout1 to TL074 but only attached the probe on the pin
I really don't think that probe will make any sinking current to refout1 as well as high imedance input of the Opamp
any idea or more related document about refout1 is appreciated
thank you
It is strange to see such a failure. Actually in a lot of experiment, we monitor Vref.
could you please share the full application circuit? you can send it to me via chris.qin@analog.com
regards