You can set the schematic editor to one of two modes to select whether you are using the SIMetrix native (SPICE) simulator or the SIMPLIS simulator. To create a new schematic in SIMPLIS mode, click File | New | SIMPLIS Schematic. To create a new schematic in SIMetrix mode, click File | New | SIMetrix Schematic.
To switch from SIMPLIS mode to SIMetrix mode, select Simulator | Switch to SIMetrix mode and to switch from SIMetrix mode to SIMPLIS mode, select Simulator | Switch to SIMPLIS mode.
If you change modes while the schematic contains devices and parts, the program will check all the parts to see if they are compatible with the newly selected simulation mode or not because not all parts will work in both modes. Any parts or devices that are not compatible will be highlighted and a warning will be issued. You will likely need to replace those parts that are highligted. To clear the highlighting, select Edit | Unhighlight (All Open Sheets).
If you wish to enter a circuit that will work in both modes, you should enter it in SIMPLIS mode and not use any of the parts in the menu Place | SIMPLIS Primitives or Place | Digital except Place | Digital | SIMetrix Compatible Logic Gates. This will minimize the chance of placing a device that is compatible with only one simulator.
If you primarily use SIMPLIS, you may want to select SIMPLIS as the default simulator for all new schematics. To do this, File | Options | General… then select SIMPLIS for the Initial Simulator setting.
SIMPLIS analyses are setup using the same menu as SIMetrix but you must first set the schematic to SIMPLIS mode. Select menu Simulator | Choose Analysis…..
SIMPLIS has three analysis modes. On the right side of Choose SIMPLIS Analysis dialog box you will see Periodic Operating Point (POP), AC, and Transient options. POP is a unique analysis mode that finds the steady state of a switching circuit. AC finds the small signal response of a periodic system and transient is similar to SIMetrix transient analysis.
SIMPLIS Transient Analysis
To setup basic transient analysis:
- Click on the Transient tab.
- Check the Transient box in the Select analysis.
- Enter an appropriate stop time under Analysis parameters.
- Enter an appropriate selection under Save options. Select All saves all data for subsequent plotting.
Periodic Operating Point Analysis (POP)
To setup POP analysis:
- Check the POP box under Select analysis in the Choose SIMPLIS Analysis dialog box.
- Click Periodic Operating Point tab.
- Under POP Trigger source, check the Use "POP Trigger" schematic device box. You will need to place a POP trigger device on your schematic.
- In the Maximum period box, enter a value that is larger than the largest possible value of your circuits switching period.
You must place a POP trigger device in the schematic. Click Place | Analog Functions | POP Trigger. After placing the device, connect its input to a switching frequency signal. You do not need to connect the output of this device. Select the trigger device then press F7. Enter suitable values for Ref. Voltage and Hysteresis so that it will reliably trigger on the switching waveform. If you don’t use the output, there is no need to change the other parameters.
To setup AC analysis:
- Check the AC box under Select analysis in the Choose SIMPLIS Analysis dialog box.
- Click AC tab.
- Enter parameters in Sweep parameters section.