Why do i get a zero before the first pole?

[demodb]

question about zero

He guys,
when I simulate this circuit I get a zero before the first pole. Any one has an idea why this happens. I don’t see any forward paths in this which can cause it. Or am i just looking at it the wrong way.
Hope some one can shed some light into this.

 

[Miguel Gaspar]

question about zero

No values for sources.
WHat programa did you use to simulate this?

 

[demodb]

Re: question about zero

The simulations were done with microcap. The values used are I1=20u [A], I2=5u [A] and Vdd=5 [V].

 

[Miguel Gaspar]

question about zero

Well I already simulate with LTspice and ran very well.

 

[demodb]

Re: question about zero

thx for testing it. Guess i made some mistake then, microcap should be able to simulate it too. Will let you know if i found out what i did wrong.

 

[VSMVDD]

Re: question about zero

maybe you need to use vdd=+5[V]


maybe its stupid

 

[Miguel Gaspar]

Re: question about zero

You can enter to Linear technologies web and download this simulator

https://www.linear.com/designtools/softwareRegistration.jsp

Added after 1 hours 1 minutes:

there you have the results: