Casting the derivative of a voltage to a voltage brings about a "singular matrix" issue in NGSPICE and fails to converge.
Here's a test file debug.va
`include "discipline.h"
module modulename (x,debug);
inout x,debug;
electrical x,debug;
parameter real alpha=0.2;
analog begin
//I(x) <+ ddt( V(x) );
V(debug) <+ ddt( V(x) );
end
endmodule
I simulated with the file bench.sp:
V0 x 0 SIN 0 20 100 0 20
NDUT x debug coco
.model coco modulename
.control
pre_osdi debug.osdi
tran 1e-6 100e-3
plot v(x)
plot i(V0)
nodeset all=0;
.endc
.end
On the other hand, the commented line, casting the derivative of a voltage to a current, behaving like a capacitor, works fine.
I am using ngspice-44 and openvaf 23.5.0.
Casting the derivative of a voltage to a voltage brings about a "singular matrix" issue in NGSPICE and fails to converge.
Here's a test file debug.va
I simulated with the file bench.sp:
On the other hand, the commented line, casting the derivative of a voltage to a current, behaving like a capacitor, works fine.
I am using ngspice-44 and openvaf 23.5.0.