Hi folks,

I have a dilemma here and I need help. In my knowledge, Vol is the measurement of DUT output wrt the negative supply. The passing limit of my Vol is 0-60mV. The typical is about ~40mV. But during my simulation in NI multisim, the value I get rails to 1.808. Hoping that somebody could help me on this.

Here is the configuration:
Vs = +/-0.9V
Il = 1mA
Vcntrl = >0.9V w/c I set to 1.9V

The attached the config in multisim.

 

There is no fdbk around the DUT so its output is Aol x Voffset.

I must be missing something. I can see there is a delay as bias
current will be charging DUT input caps, But no predictability of its
sign. And Vos always present.


Regards, Dana.

 

What is V1 suppose to do? I don't understand the offset within the loop. Also, why I1?

 

What is V1 suppose to do? I don't understand the offset within the loop. Also, why I1?

It is a value set by the tester and program, what I do is replicate the results of the tester using bench test. But before I bench test it, I must assure it works fine with simulations otherwise I am bench testing for nothing.

 

There is no fdbk around the DUT so its output is Aol x Voffset.

I must be missing something. I can see there is a delay as bias
current will be charging DUT input caps, But no predictability of its
sign. And Vos always present.


Regards, Dana.

The whole configuration is the schematic used in the tester and program. I just replicated it in simulation. But instead of getting the same value with the tester result, I obtain a far from real data result.

 

See

 

See
View attachment 181048

The reading of Vol should be connected to the output of AD8619 wrt Vs=-0.9V not ground.

 

This isn't my land. The symbol of the earth I have (LTspice) is a triangle.

 

See