Download - SIMetrix

User’s Manual
probe afterwards. Alternatively, you can place - say - a single fixed probe on an
obvious point of interest, then randomly probe to investigate the detailed behaviour of
your circuit.
Fixed schematic probes are limited to single ended voltages and currents and
differential voltages. The random probing method allows you to plot anything you like
including device power, FFTs, arbitrary expressions of simulation results and X-Y
plots such as Nyquist diagrams. It is possible to set up fixed probes to plot arbitrary
expressions of signals but this requires manually entering the underlying simulator
command, the .GRAPH control. There is no direct schematic support for this. For
details of the .GRAPH control see the “Command Reference” chapter of the Simulator
Reference Manual.
Fixed Probes
There are several types of fixed probe. Three of the commonly used probes are:
1.
Voltage. Plots the voltage on a net.
2.
Current. Plots the current in a device pin.
3.
Differential voltage. Plots the voltage difference between two points.
They are simply schematic symbols with special properties. When you place a fixed
probe on the schematic, the voltage or current at the point where you place the probe
will be plotted each time you run the simulation. The probes have a wide range of
options which can be set by selecting the probe then pressing F7. These options are
covered in detail in section “Fixed Probes” on page 209.
There are more fixed probes available in addition to those described above. See “Fixed
Probes” on page 209 for details.
Fixed Voltage Probes
You can place these on a schematic with the single hot key ‘B’ or with one of the
menus
Probe|Place Fixed Voltage Probe...
Place|Probe|Voltage Probe
schematic popup Probe Voltage
Hint
If you place the probe immediately on an existing schematic wire, SIMetrix will try
and deduce a meaningful name related to what it is connected to. If you place the probe
at an empty location, its name will be a default (e.g. PROBE1-NODE) which won't be
meaningful and you will probably wish to subsequently edit it.
Fixed Current Probes
You can place these on a schematic with the single hot key ‘U’ or with one of the
menus
56