White Mountain Labs – Transmission Line Pulse TLP Testing Overview
Transmission Line Pulse testing, or TLP testing, is a method for semiconductor characterization of Electrostatic Discharge ESD protection structures. In the Transmission Line Pulse test, high current pulses are applied to the pin under test PUT at successively higher levels through a coaxial cable of specified length. The applied pulses are of a current amplitude and duration representative of the Human Body Model HBM event or a Charged Device Model – CDM – event in the case of Very Fast TLP, or VF-TLP. The incident and reflected pulses are evaluated, and a voltage-current V-I curve is developed that describes the response of an ESD protection structure to the applied TLP stresses. The Transmission Line Pulse test is unique because the current pulses can be on the order of Amps, and the TLP test results can show the turn-on, snap-back, and hold characteristics of the ESD protection structure.Transmission Line Pulse testing is useful in two very important ways. First of all, TLP may be used to characterize Input/Output I/O pad cells on test chips for new process technologies and Intellectual Property IP. TLP is very useful in developing simulation parameters, and for making qualitative comparisons of the relative merit of different ESD protection schemes for innovative pad cell designs. Secondly, TLP may be used as an electrical failure analysis tool, often in combination with conventional, standards-based component ESD testing.A standard practice for TLP testing is available on the ESD Association web site at http://www.esda.org. The TLP test method is: ESDA SP5.5-2003When qualifying a TLP test service, several important factors should be considered: a the technical expertise and experience of the engineering staff, b the quality practices, such as ISO 17025 accreditation, and c the availability of industry-standard ESD test services on-site.