49 lines
2.4 KiB
Plaintext
49 lines
2.4 KiB
Plaintext
ACS is a general purpose circuit simulator. It performs nonlinear
|
|
dc and transient analyses, fourier analysis, and ac analysis
|
|
linearized at an operating point. It is fully interactive and
|
|
command driven. It can also be run in batch mode or as a server.
|
|
The output is produced as it simulates. Spice compatible models
|
|
for the MOSFET (level 1 and 2) and diode are included in this
|
|
release.
|
|
|
|
Since it is fully interactive, it is possible to make changes and
|
|
re-simulate quickly. The interactive design makes it well suited
|
|
to the typical iterative design process used it optimizing a circuit
|
|
design. It is also well suited to undergraduate teaching where
|
|
Spice in batch mode can be quite intimidating. This version, while
|
|
still officially in beta test, should be stable enough for basic
|
|
undergraduate teaching and courses in MOS design, but not for
|
|
bipolar design.
|
|
|
|
In batch mode it is mostly Spice compatible, so it is often possible
|
|
to use the same file for both ACS and Spice.
|
|
|
|
The analog simulation is based on traditional nodal analysis with
|
|
iteration by Newton's method and LU decomposition. An event queue
|
|
and incremental matrix update speed up the solution for large
|
|
circuits.
|
|
|
|
It also has digital devices for mixed signal simulation. The
|
|
digital devices may be implemented as either analog subcircuits or
|
|
as true digital models. The simulator will automatically determine
|
|
which to use. Networks of digital devices are simulated as digital,
|
|
with no conversions to analog between gates. This results in
|
|
digital circuits being simulated faster than on a typical analog
|
|
simulator, even with behavioral models. The digital mode is
|
|
experimental and needs work. There will be substantial improvements
|
|
in future releases.
|
|
|
|
ACS also has a simple behavioral modeling language that allows
|
|
simple behavioral descriptions of most components including capacitors
|
|
and inductors. Unfortunately, it is not well documented.
|
|
|
|
ACS uses an object oriented approach to modeling. Complex models
|
|
like MOSFETS are made of simpler ones like resistors, capacitors,
|
|
diodes, and any other models that may already exist. The model
|
|
designer does not need to worry about details like convergence
|
|
checking, bypass checking, integration, or how the new device plugs
|
|
into the solution matrix because these are already taken care of
|
|
by the basic models. This results in a dramatic improvement in
|
|
the time it takes a researcher or model designer to install a new
|
|
model, compared to Spice.
|