Technical Report - , October 12, 2005.
RF Integrated Systems & Circuits (RISC) Division, Aalborg University, Denmark.
Most of the free simulation packages are based on a SPICE (Simulation Program with Integrated
Circuit Emphasis) simulation engine. This implies that all simulations take place in the time-
domain. In contrast to this some tools make use of the frequency-domain for the circuit analy-
sis. As always there are pros and cons for either approach.
This report provides a short introduction to one of the many free simulation software options,
LTspice. The software is provided by Linear Technology
1
and it comes without any limita-
tions to its use. It should be noted that the graphical user interface (GUI) does not offer access
to the complete range of functionalities available in LTspice. Despite this fact LTspice does
offer the complete range of SPICE functionalities. The only thing to rememer is that some func-
tions are available through the ’SPICE directives’ option only. It is also worth noticing
that the help functionality of LTspice is quite extensive and it provides for good documenta-
tion of the program.
Updated information on where to find the software and how to install it is available at the
following www location:
http://kom.aau.dk/∼hmi/Teaching/LTspice/LTspice_Intro.html
There is also an LTspice faq available. Here known issues and different solutions and work-
arounds are presented. The page is constantly updated and it is found at the following www
location:
http://kom.aau.dk/faqomatic/cache/198.html
This version of the LTspice introduction document referrers to LTspice version 2.15z, Au-
gust 15, 2005
Jan H. Mikkelsen, Aalborg, October 2005
1
http://www.linear.com
JAN HVOLGAARD MIKKELSEN PAGE 3
