Tool/software:
Hi TI expert
I found the application report ZHCA658 from TI website to study the RC snubber circuit design.
In the section 1.3, it gives the formula of the equivalent circuit[figure 3], and the selection guide of the Rsnub value, that is Rsnub >= 0.5*sqrt(Lr / Cr) [equation (2)].
from my understanding, in order to reduce the resonance, the RLC circuit should be critically damped or overdamped, and then the characteristic root S1 and S2 of the characteristic equation should be equal negative real numbers or unequal negative real numbers, so the value of R should be less than 0.5*sqrt(Lr / Cr). You can find my calculation from the attachment.
the above is the understanding from mathematical calculation. In addition, if follow the equation (2) Rsnub >= 0.5*sqrt(Lr / Cr), set the value of R to infinity, it will be the open circuit, so, how does added RC snubber circuit work? nothing will be.
So, I think the equation (2) in this application is wrong, do you have any other idea?
