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Simulation of an Inverter

In this tutorial, we will create an inverter schematic, symbol and a testbench to run a transient simulation on the inverter schematic.

Schematic and Symbol Creation

  • Make a new cellview as in the "Run DC simulations" case and name it "inv." Build the inverter schematic as shown below:

  • Add pins from "Create >> Pin". Choose input direction for (in, vdd, vss) and output direction for (out). Save your work.

  • To create a symbol for the schematic go to "Create >> Cellview >> From Cellview", click OK on the next two popup windows.

  • Edit the the symbol into something more representative of the schematic. (m, M to move, s to stretch, r to rotate, and line, and shapes in the tool bar). An edited version of the inverter symbol is shown below. Check&Save your symbol.

 

Transient Simulation Testbench

  • Make a new schematic cellview and name it "inv_test." Bring in the inverter symbol you created in the previous step using "Create >> Instance." Add 1V and 0V DC source lik in the "Run DC simulations." A a transient pulse source and set up its parameters as shown below.

  • Add a capictive load on the inverter, and use "cload" a variable for the capacitor value.

  • Launch ADE L and copy the simulation variables in (Variables >> Copy From Cellview) and set the load capicitance to 10f and period to 500p.

  • Choose a transient analysis (Analyses >> Choose) and set it up as shown below. Save "vin" and "vout" and select it to plot too.

  • The simulated resulted should look the waveforms below.

  • Save this simulation state ("Session >> Save State") and choose a descriptive name for this state and hit OK.

 

DC VTC Simulation

  • In the inv_test schematic view, add a DC source with a value "dcin." Label its out "vindc" and switch the inverter input label to same node.

  • In ADE L, add the new node "vindc" to saved outputs and deselect vin from plot and copy "dcin" from the cellview set it to 0.

  • Add a DC analysis to ADE L and set it up as shown below. Click OK. Disable the transient simulation.

  • Run the simulation, and the result will show the inverter VTC as below

  • To see the gain of the inverter, you can use the calculator to find the derivative of the dc output. ("Tools >> Calculator"), Pick "vs" and select "out" from the schematic. In the Function Panel of the Calculator, choose "deriv" and hit plot