New Closed-Form Formula for Series Inductance and Shunt Capacitance Based on Measured TDR Impedance Profile

Time domain reflectometry has been widely used to characterize high speed interconnects. The equivalent lumped LC model is then developed based on the measured impedance profile (Z-profile). However, for discrete L or C, mounted in the middle of transmission line interconnects, the current formula based on Z-profile cannot provide correct results. In this letter, a new closed-form formula based on the Z-profile is derived to determine the lumped L or C with the rise time of the incident step taken into account, which is easy to integrate into any EDA tools.