In "ESD in silicon integrated circuits", A.Amerasekera & C. Duvvury (p.12 - [2.1]) there is a solution for LCR curcuit (
www.ieek.or.kr/ICEIC/upload/AP-LimHoJeong195__.doc ) :
i = Vc*Cc*pow(w0,2)/sqrt(pow(a,2)-pow(w0,2))*exp(-a*t)*sinh(sqrt(pow(a,2)-pow(w0,2))*t)
with a = R/(2*L1) and w0 = 1/sqrt(L1*Cs) and a>w0.
So, this expression give strange result with my parameters (R1 = 1.5k, Cc = 100p, L1 = 9.9u, Cs = 1p, Ct = 10p, R = 500).
Can you explain how was this formula obtained ?