# LION COMMUNITY USAGE CASE

### Simulation-based Optimization of Electronic Circuits.

### Integrated circuit and board-level design simulators.

It is not practical to prototype
integrated circuits before manufacture, and the high costs of photolithographic masks
and other manufacturing prerequisites make it essential to design the circuit to be
as close to perfect as possible before the integrated circuit is first built.
**Simulators** like SPICE (starting 1973) are the industry-standard way to verify circuit
operation at the transistor level before committing to manufacturing an integrated circuit.

Given a list of parameters about a specific design, a simulator derives the ** behavior ** of
the circuit, for example the waveform obtained at a circuit output.

### Simulation-based optimization with LIONoso.

When a **desired behavior** is given, software for automated optimization can help
in designing an optimal circuit by testing many different combinations of design parameters, for
sure many more than a human person can consider. In addition, intelligent optimization schemes
like LIONoso can generate the different combinations of design parameters **in a strategic manner**,
aiming at an efficient use of all information obtained during the previous simulations.

The first step consists of loading the circuit simulated by SPICE as an external *
shell-executable function* and connecting it to the ** RSO (Reactive Search Optimization) ** module.
After the RSO module is started the first design solutions are generated.

### Visualizing the behavior of the designed circuits.

For this problem, visualizing a single solution can be done with the tools of LIONoso, for example by
generating tables of the gain as a function of the different frequencies.
But there is a more interesting possibility: to visualize different solutions, by clicking on
balls in the Pareto-optimal points (the set of non-dominated alternatives). This can be done by the
**parametric table** tool in the * Table manipulation and creation folder*. When connected to the
optimization results table it creates data referring to the particular solution chosen (by clicking on it).

After the different components are connected, we can now start analyzing the different solutions, just by clicking.
For example, when solution labeled * Row12 * is clicked, one of the non-dominated solutions is shown at the right,
when solution labeled * Row3 * is clicked, a dominated (inferior) solution is visualized.

Please contact us if you are interested in the details
of this usage case and we will be happy to
send you more details. The optimization and analysis tools of LIONoso can be used for
other ** circuit design software ** in addition to SPICE.

**References:**

SPICE (Simulation Program with Integrated Circuit Emphasis)