Evaluating TLP transients and HBM waveforms

Transmission Line Pulsing (TLP) is capable of determining a true impedance function in the s-domain, including time-dependent transients, as Z=Z
₁
(1+as+bs
²
+...), with nonzero s-coefficients. We show how to determine the Z
₁
and a terms and how to find more terms if desired, for long and short TLP pulses, drawing on network theory and approximation methods. We apply these to examples of inductive delay in devices. The same kind of methods are used to remove the effects of measurement tools themselves, including finite rise time of the TLP pulse and voltage droop of a current transformer. Then the true RC time constant of an HBM waveform is extracted as a network coefficient, through methods developed in this work.