6.1 Simulating Non-Inverting PGA in Mindi™

Todo:
  • Download the pre-made non-inverting PGA simulation file containing the AVR DB op amp model
  • Run the simulation
  1. Go to github.com/microchip-pic-avr-examples/avrdb-opamp-mindi-non-inverting-pga/releases and press the Source code (zip) link to download the simulation.
    Info: All the pre-made simulations can be found at github.com/search?l=&q=org%3Amicrochip-pic-avr-examples+avrdb+in%3Aname+extension%3Awxsch&type=repositories.
  2. Unzip the folder to your location of choice.
  3. Open MPLAB® Mindi™, press File→Open or Ctrl+o, and locate the file Non_Inverting_PGA.wxsch in the location where the zip file was extracted.
  4. Simulate by pressing the Run Schematic button.
    Result: If everything worked correctly, the plot of the simulation, as shown in Figure   1, should come up.
    Figure 6-1. Assignment 4: MPLAB® Mindi™ Plot
  5. Change the resistors R1_OP0 and R2_OP0 to the once corresponding to WIP3. This will set the gain to 2x.
  6. Simulate with the new resistor values by pressing Run Schematic.
Result: The plot in MPLAB® Mindi™ should look similar to the one in Figure   2, where the red waveform is the output from the op amp, and the green is the input. As expected, the output is twice as large as the input.
Figure 6-2. Assignment 4: Mindi™ Result