Solving the second order differential equation:
d2V/dt2 + (1/RC) dV/dt + (1/LC) V = 0
Requires finding the roots of the characteristic equation:
s2 + (1/RC) s + 1/LC = 0
If the roots are:
Real and different or distinct (s1, s2): v(t) = A1es1t + A2es2t
Real and equal (s1 = s2): v(t) = D1te-αt + D2e-αt
Complex (s1, s2): v(t) = B1e-αt cos ωdt + B2e-αt sin ωdt
where:
α = the neper frequency = 1/2RC
ωd = the damping frequency = sqrt (ωo
2 – α2)
ωo = the resonant frequency = 1/sqrt (LC)