timestep too small (chopper stabilized amplifier)

[tiger66]

Hi All
I am trying to design a chopper stabilized amplifier using Multisim 7.

My circuit works before the amplifer stage. Today, I added a modulator, and every time I simulate, I get a "timestep too small" error message.

I tried increase the end time in transient analysis setting, but nothing works

I attached my circuit to this email, could someone please give me some assistant? I would be really appreciated

Thanks

[Tien_P]

Try the steps described in this knowledge base, I hope it will help.

http://digital.ni.com/public.nsf/allkb/4B99B2CD6C0C3B6A86257205005D58E0


I tried simualating your file on and it did not give me any error.

[tiger66]

Hi Tien
What verion of multisim are you using? I am using Multisim7

I tried the steps in the knowledge based for fixing the timestep too small problem, unfortunately, it still can't solve the problem

For circuit4, I need to modify my Voltage control voltage source in order to fix the problem.

Now, I add a demodulator to my circuit which is just the same circuit as the modulator. Unfortunatly, I am getting the same "time step too small" problem again

Is there any other way to resolve this problem? I am running out of idea 😞

I attached my circuit with the message,  thanks in advance for your help

[Tien_P]

I don’t think you will be able to fix this circuit by changing the simulation settings, this looks like a model issue.  I replaced the MOSFET model and this circuit is now running.

Message Edited by Tien P on 04-03-2007 03:33 PM