AnsweredAssumed Answered

AD5781 VREFNF can not be setted to 0V.

Question asked by BOEING on Apr 13, 2017
Latest reply on Apr 17, 2017 by msamera

Dear Engineer:

     Hi!

   I connect the AD8062AR to the AD5781ARUZ by following the instruction of AD5781ARUZ. What I want to achieve is to make the VREFNF to 0V. The diagram about negative connection is shown in below:

 

    a.jpg.png

 

The connection about positive connection is shown in below:

    b.jpg.png

 

 

实际中我用的运放不是AD8062,而是LF412

In realistic the OPAMP I used is not AD8062 but LF412. During the test, the voltage of eight U3 pins I measured is shown as the list below:

Pins Voltage

 

1 0.48

2 0.00

3 0.00

4 -15.02

5 5.01

6 5.00

7 5.00

8 15.11

We can see that the voltage of VREFNF is not 0V, but 0.48V. What caused?

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