Simulation of Created Design
Documentation on the simulation process of a basic
injector-separation channel model design
The Simulation Process
In this simulation, a sample will be passed into the injector, and ‘Injected’ into the separation channel
This is where the different species of the product will begin to separate from each other
A signal of when each species passes a detector will be taken and plotted
Getting to the Simulation Window
In order to simulate the design, the simulation window named “Cadence Analog Design Environment” needs to be opened
To do this, go into the toolbar menu: Tool-> Analog Environment
Getting Variables
The Variables that were used when adding the objects need to be added into the simulation variables
This is done by selecting Variables -> Copy From Cellview from the toolbar, this will pick all the variables in the schematic
Editing Variables - I
Now the values of those variables need to be changed To change them select Variables -> Edit from the toolbar, or
click on the following side toolbar button
Editing Variables - II
To change the values, type the value into the Value (Expr) field and click on Change
Then select the Next variable from the table and continue
Enter the following table of values, V1D and V3D
need to be close to V4D value to prevent much of a voltage difference between the two
V4L 12.5
V4D 3000
V3L 0
V3D 2900
V2L 52.5
V2D 0
V1L 22
V1D 2900
mu0 50000
mu1 40000
LOAD
0
D1 400
D0 400
Selecting Outputs
In order to neatly see the results from the simulation, outputs are needed
To select output, in the toolbar menu, go to:
Outputs -> To Be Plotted -> Select On Schematic This will open up the schematic window again
Selecting the Pin
In the Editor window, the values of wire that is selected will be plotted in a graph when the simulation is run
So, select the ‘conc<0:1>’ output pin on the first detector and the ‘conc_out<0:1>’ output pin on the second detector
Output Plots
When the conc<0:1> pin is clicked a box pops up and when it is clicked again, conc<0> and conc<1> get highlighted, click OK, the two come under Outputs follow the same procedure for conc_out too
Choosing the Analysis
To select the simulation type, click on the “Choose Analyses...” button on the side toolbar
The DC Analysis
In the “Choosing Analyses” window, select dc, Enabled, and Save DC Operating Point and click OK
The First Simulation
Once all the values have been inputted, click on the toolbar menu: Simulation->Netlist and Run on the toolbar menu or click the “Netlist and Run” button on the side toolbar
The Log File
After this simulation has been run, a log file will appear This file is the results of the simulation and has some values
that need to be inputted into the design
Edit the Properties
Some properties of the injector need to be changed To do this go to: Edit -> Properties -> Objects… q
Editing Properties
Input the values from the log file of the currents and concentrations into the corresponding properties of the injector, i.e.,
current 1 = cur_I1 etc One change that needs
to be done to the values is that they should all be inputted as positive numbers
Transient Simulation
In the “Choosing Analyses” Window, Select tran and Enabled, then set the Stop Time to ‘1.5’, check conservative, and click the Options... button
Editing the Transient Simulation
In this window, Set the start field to 0, and set the values of the step and maxstep fields to ‘.001’
Then click OK and get back to the simulation Window
Simulating
Once all of the values are inputted, the only thing left to do is to simulate
This can be done by clicking on the Netlist and Run on the side toolbar button
This simulation may take a little longer than the previous one
The Final Output
After the Simulation finishes, a ‘Waveform Window’ will appear with the desired plot on it
This plot shows the outputs at the selected pin
Understanding the plot
Click on the Curves-> Edit and we will be able to set some outputs to off and on to better understand the plot
Increase the number of data points by going to “Cadence Analog Environment window” selecting Analysis in the side toolbar and clicking Options and changing the step and max step to get a more accurate plot
Changing the voltages may increase or decrease the time the species tested need to approach the detector
Change in the mobilities might separate or reduce the space between the two species
Finishing up
Now we will save the current state of the simulation Go to Session->Save State … and save it as state2