Hi, I'm trying to amplify and shift a voltage input of 0 to 0.35V to 0.25 to 5V using only op-amps and resistors. I currently have a model (picture) but the simulation is giving me an error " Voltage source and/or inductor loop involving E_U3". I set up a DC sweep of the input voltage from 0 to 0.35V.

Is there a simpler way to do this?

 

You have tied the output of U3 to ground.

Edited to add: Yes, there us a simpler way to do it using only one opamp. Write the function you want mathematically, then look at the equation for a summing amp, and see if you can map your function onto the summing amp.

Bob

 

hi dzss,
This is a simple option.
E

 

Hi, I'm trying to amplify and shift a voltage input of 0 to 0.35V to 0.25 to 5V using only op-amps and resistors. I currently have a model (picture) but the simulation is giving me an error " Voltage source and/or inductor loop involving E_U3". I set up a DC sweep of the input voltage from 0 to 0.35V.

Is there a simpler way to do this?

View attachment 258876

First thing to consider is "Do you really need the 0.25V offset?". If you don't it makes things much simpler and you don't need a voltage reference.