The use of the TLP testing method for electrostatic discharge (ESD) characterization of the ESD protection structures in electronic components is becoming commonplace. It has evolved from a laboratory diagnostic tool to a standard practice used for engineering evaluation and development including failure analysis and subsequent re-design for increased robustness of the protective structures. The practical basis and basics of TLP will be discussed, the different TLP configurations used for testing will be introduced, and the failure criteria will be linked to the failure criteria of the traditional HBM ESD testing. The TLP pulse parameters and testing results will be compared with that from the traditional HBM in order to show that correlation exists between the two methods of ESD Testing. Examples of TLP test results from case studies, including the subsequent failure analysis, will be presented.