Analysis dialogs
Set up and run an analysis from the Run menu.
Each dialog collects an analysis's settings and, when you press OK, runs the matching command on the current circuit, exactly as if it had been typed at the command line. The command is echoed in the message window. The results become the current plot, ready for plotting.
AC Analysis
Runs ac mode points fstart fstop; see .AC.
- Mode
dec,octorlin: points per decade, per octave, or in total.- Number of points
- The number of frequency points.
- Start Frequency, Stop Frequency
- The frequency range.
DC Analysis
Runs dc source start stop increment, with a second source if "Use Two Sweep Sources" is checked; see .DC.
- Source 1
- The independent voltage or current source to sweep, with its Start, Stop and Increment values.
- Use Two Sweep Sources, Source 2
- A second source, swept over its own range for each value of the first.
Disto Analysis
Runs disto mode points fstart fstop [f2overf1]; see .DISTO.
- Mode, Number of points, Start Frequency, Stop Frequency
- The frequency sweep, as for AC Analysis.
- Harmonic or Spectral
- Harmonic analysis of a single frequency, or spectral (intermodulation) analysis of two frequencies. For spectral analysis, F2 over F1 is the ratio of the second frequency to the first, between 0 and 1.
Noise Analysis
Runs noise V(output[,ref]) source mode points fstart fstop [pts_per_summary]; see .NOISE.
- Output Node
- The node at which the output noise is calculated. Give just the node name; the dialog wraps it in
V( )for you (a value already written asV(node)is passed on unchanged). - Use Reference Node
- Measure the output noise between the output node and this node, rather than ground.
- Source
- The independent source that is the noise input reference.
- Mode, Number of points, Start Frequency, Stop Frequency
- The frequency sweep.
- Use Points Per Summary
- Also print the noise contribution of each device every so many frequency points.
PZ Analysis
Runs pz node1 node2 node3 node4 CUR|VOL POL|ZER|PZ; see .PZ.
- Input Nodes, Output Nodes
- The nodes of the input and output ports.
- Type
- The transfer function: output voltage over input current (CUR) or output voltage over input voltage (VOL).
- Analysis Mode
- Poles only, zeros only, or both.
SENS Analysis
Runs sens output for the dc sensitivity, or sens output ac mode points fstart fstop for the ac sensitivity; see .SENS.
- Output Variable
- The output whose sensitivity is found, such as
v(out). - DC or AC
- DC operating point sensitivity, or AC small-signal sensitivity over the frequency sweep given.
TF Analysis
Runs tf output input source; see .TF.
- Output
- The small-signal output variable, such as
v(5). - Input Source
- The small-signal input source.
TRAN Analysis
Runs tran tstep tstop [tstart [tmax]] [uic]; see .TRAN.
- Timestep, Stop Time
- The printing increment and the final time.
- Start Time
- The time from which results are kept (default 0).
- Max Timestep
- The largest internal timestep; by default the smaller of the timestep and (stop time − start time)/50. If you give a Max Timestep with no Start Time, a start time of 0 is passed before it.
- Use Initial Conditions
- Skip the operating point calculation and start from the initial conditions (
uic).
OP Analysis
OP Analysis has no dialog: it runs op straight away; see .OP.