Silicon controlled rectifier (SCR) is frequently used for electrostatic discharge (ESD) protection applications. For computer-aided design purposes, a macromodel can be constructed for such a device, but a model for the NPN and PNP bipolar transistors imbedded in the SCR is required in the macromodel development. In the paper, we use both the Vertical Bipolar Inter-Company (VBIC) and SPICE Gummel-Poon (SGP) models for these bipolar transistors and compare the perspective macromodel results. Measurements obtained from the transmission line pulsing (TLP) tester are also included to assess the suitability and pros and cons of the VBIC and SGP models for the SCR ESD modeling. (C) 2008 Elsevier Ltd. All rights reserved.