Convergence Tips

If your circuit won't converge, try the following:

1. Use a piecewise linear voltage source instead of fixed supplys. Ramp them up. Note that sometimes starting with a low, but non-zero voltage works.

Examples:

V1 SLEW 0 PWL (0 1 2n 0 4n 15V)

V2 VDD 0 PWL (0 1 2n 0 4n 100V)

V3 VCC 0 PWL (0 1 2n 0 4n 15V)

V4 VEE 0 PWL (0 -1 2n 0 4n -15V)

2. Change the ITL4 seting via the .options line.

Example:

ITL4=50

Plotting Tips

Q: How to I get a listing of circuit nodes?
A: Select Analysis/Display Vectors
Note: If you select more than one analysis, the displayed vectors take this precedence:
1. Pole-Zero
2. Transient
3. Small Signal AC

A typical listing for Transient Analysis:
A typical listing for AC Analysis:

Q: How do I plot subcircuit nodes?
A: Put your node names in quotes.
Example circuit:

Now, select the menu item "Analysis/Display Vectors":

Now to plot the subcircuit node #3:
In the plot command edit box, type "V(1:3)"

Note: Subcircuit nodes that are available externally are not available. I.E. in this case, nodes 1, 2, 99, 50, and 28 are not available.