User`s guide

Thin

s to Watch For 3

-33

Missin

DC Path to Ground

If for selected nets in your circuit you see this message in the

PSpice output file,

ERROR -- Node

node_name

is floating.

then you may be missing a DC path to ground.

Check for this

Are there any nets that are isolated from ground by either open

circuits or capacitors?

If so, then add a very large (for example, 1 Gohm) resistor

either:

• in parallel with the capacitor or open circuit, or

• from the isolated net to ground.

Example: The circuit shown below connects capacitors (DC

open circuits) such that both ends of inductor L2 are isolated

from ground.

When simulated, PSpice A/D flags nets 2 and 3 as floating. The

following topology solves this problem.

This applies to analo

-only and

mixed-si

nal circuits.

Note

When calculatin

the

bias point solution, PSpice A

D treats capacitors as open

circuits and inductors as short

circuits.