The assignment is to create a Digital to Analog Converter (DAC) using a Summation Amplifier in PSpice. It is a 3-bit input DAC. Output step range is 0 V to -3.5 V, where input bits are 0 V for '0' and 5 V for '1'. We have to assume that the Op-Amp is dual powered using + and - 10 V. And we must include a compensation resistor. I've done this in PSpice. But PSpice is the devil. It keeps saying the Dual Powered Op-Am I'm using "cannot be simulated". Can anyone advise how to modify the schematic to fix it?

I'm posting my design thus far. It is a work in progress.



I saw this design and want to modify my design to include a similar battery type as the one pictured. Any suggestions on how to accomplish that in PSpice?



Thanks for the help!

 

It sounds like perhaps you aren't specifying a model for your opamp that is in your library.

 

I figured it out. I had to name the pins in the schematic in order to get the simulator to run. I also switched the amplifier with a uA741 op amp. In order to get the necessary output, I used a V-pulse source.