Please note that the Mextram model is subject to licensing, see the Mextram copyright notice

Introduction to Mextram

The Mextram model gives an excellent description of vertical bipolar transistors in all kinds of processes, amongst which are modern SiGe processes and robust HV processes. It is very efficient in modelling the lowly doped collector epilayer of a bipolar transistor where effects like velocity saturation, base widening, Kirk effect, and impact ionisation play a role. Effects due to having Germanium in the base are also modelled. Furthermore, it contains a full description of the extrinsic regions of a transistor, including substrate current and capacitance. Mextram has formulations for temperature scaling and is easily scalable over geometry. Mextram, level 504, includes full self-heating, in contrast to having self-heating handled by the circuit-simulator. Self-heating is completely implemented in the source code.

Read more about Mextram.

Model definition of Mextram

The model definition of Mextram is available in the following PDF files:

The history of the model can be found here.

Source Code & Library

The source code of Mextram is available here
The file called "device_t504i.c" contains the majority of the Mextram 504 code. If you use the included solver, please make sure that you compile on a system that supports Fortran 77.

The history of the source code can be found here.

The models are included in a dynamically loaded library called SiMKit.

SiMKit is related to the following circuit simulators used within NXP:

  • Pstar, the circuit simulator from NXP
  • Spectre, the circuit simulator from Cadence
  • ADS, the circuit simulator from Agilent

You can read how to download and install the libraries here.

The source code is protected by Copyright © 1991, 2007, NXP.

Additional documentation

Further information on Mextram is available in the following additional documentation:

Related Publications

Further information on Mextram is available on the Mextram documentation page, as well as in the following related publications below:

© 1989, 2007 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

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