open-source-silicon.dev

Comp4S (1).PNG

It is possible to graph I(M2) vs I(M8)? using xschem and ngspice?

you can also place a voltage source with voltage 0, then plot i(Vn)

i don't think ngspice calculates currents unless you tell it to by using an ammeter or voltage source

1.png

You can create a graph in xschem and change the sweep variable, This example plots drain current of mos1 vs mos2

2.png

You need to specify the `sweep` variable in the graph dialog box. Double click in the middle of the graph to bring it up:

You can do this also in ngspice: `plot i(vd1) vs i(vd2)`

I usually place ammeter devices as <@U03QSBWN0TU> suggested because the syntax for  ammeter current is simple, while referencing a mos drain current is very complex and ngspice specific. If you port the design to Xyce it will not work.