In this topic:
SIMetrix features a common sweeping algorithm which is used to define the swept analysis modes: .DC, .AC, .NOISE and (now) .TF, along with multiple analyses such as Monte Carlo.
The sweep algorithm has 6 modes:
As well as providing 6 modes, each of the modes can sweep in four different ways. These are linear, decade, octave and list.
All the swept analysis modes use the same general syntax to specify the sweep parameters. However, to maintain compatibility with SPICE and its derivatives including earlier versions of SIMetrix, each analysis mode allows variations to this standard syntax. The general syntax is described below while the variations allowed for each analysis mode are described in the section dedicated to that analysis mode.
All of the analysis modes can optionally be entered in a similar manner to .MODEL statements i.e. as an unordered list of parameter names followed by their values. For example, the following is a perfectly legal noise analysis specification:
.noise V=vout DEVICE=V1 VN=0 F=1k LIN=(100 -10m 10m) + INSRC=V1
In the various forms of the syntax described in the following sections, some of the parameter names may be omitted as long as they are entered in a particular order. It is sometimes, however, easier to remember parameter names rather than a default order, so the method described above may be more convenient for some users.
.AC|.DC|.NOISE|.TF sweep_spec [ analysis specific parameters ]
sweep_spec: One of the following:
DEVICE device_name step_spec F frequency TEMP step_spec F frequency PARAM param_name step_spec F frequency MODEL model [PARAM] mod_param_name step_spec F frequency FREQ step_spec MONTE num_steps F frequency
Where
| device_name | Name of device to be swept. The following components may be swept: Capacitors, all controlled sources, fixed current source, fixed voltage source, inductors and resistors. |
| param_name | Name of parameter used in expression. Expressions may be used to define an instance or model parameter and may also be used in arbitrary sources. |
| model | Name of model containing parameter to be swept |
| mod_param_name | Name of model parameter |
| num_steps | Number of steps to be performed for Monte Carlo sweep. |
| frequency | Specified frequency for which .NOISE, .AC and .TF analyses are to be performed. May be zero for .AC and .TF. |
| step_spec | See below |
step_spec is defined as follows:
STP start stop step LIN num_points start stop DEC num_points_decade start stop OCT num_points_octave start stop LIST val1 [ val2 ... ]
Where:
| start | First value |
| stop | Last value (inclusive) |
| step | Interval |
| num_points | Total number of points |
| num_points_decade | Number of points per decade |
| num_points_octave | Number of points per octave |
| ◄ Overview | Multi Step Analyses ▶ |