Hi Jeffrey,

If you are referring to the transient current generated every time the inverter switches, then it is ok not to see any current being provided by the bypass cap. The reason is simple: the voltage across the cap is constant, and since the current through a cap is given by the rate of change (slope) of the voltage across it, then that current will always be 0.

Instead of using an ideal voltage source (which can provide transient currents as fast as you want) you could put a series resistor in between the voltage source and the cap. If the transient current is fast enough it will be the cap who is going to provide it.

Tosei.

Jeffery,

   Sorry happy fingers:

3) Design of the bypass network
   a) Location of the bypass capacitors: on-chip or off-chip
   b) For off-chip capacitors, the type of capacitors used
       different capacitors have different characteteritics, ESR, ESL, ...
   c) For on-chip capacitors, use device models do not use ideal
       capacitors, for example, a MOS gate capacitor value is bias
       dependent
 
2) one other thing I forgot,
   f) include the effect of the on-chip power supply routing

  The list is fairly exhaustive and not all effects need to be included,
but, what needs to be included is design specific. You need to think
carefully about what you are trying to simulate and build a model for
the power supply distribution systems that accurately reflects the
implementation.

                                                          Best Regards,

                                                             Sheldon