how to implement this function?

[samuel]

(1) The initial value of a capacitor is 5V;

(2) Then a constant current discharge this capacitor, the discharge waveform is as Fig.1

(3) This discharging current consists two part, I=Ibak+Isig.

(4) Now, we can sample this capacitor respectivly at t1 and t2.

My question is how to get the voltage Isig generated at the capacitor excludes the voltage Ibak generated at the capacitor?

thanks.
samuel.

 

[leo_o2]

copy the current Ibak, charging a cap with same value as sampled cap from t1 to t2. You can get a voltage Vx on the cap.
V(t1)-V(t2)+Vx is what you want.

 

[gpwu]

1. put Isig=0, measure V(t2-t1)=dv1
2. add normal Isig, measure V(t2-t1)=dv2
Then the dv2-dv1 should be Isig's contribution