On Wed, May 18, 2005 at 12:29:27PM +0200, Davide Anastasia wrote: > Il giorno lun, 16-05-2005 alle 21:08 -0400, Daniel Nilsson ha scritto: > > On Tue, May 17, 2005 at 12:52:57AM +0200, Davide Anastasia wrote: > > > Il giorno lun, 16-05-2005 alle 21:24 +0200, Leva ha scritto: > > > > ..of what? > > > > > > I've got only a schematic... It's possible to perform this task with > > > Spice? > > > Anyone can help me to find the error in this netlist? I'm a beginner of > SPICE :( > > Filter Net > Vb 1 0 DC 4.5 > Vin in 0 DC 4.5 AC 4.5 > C1 in 2 22N > C2 2 3 22N > C3 3 out 22N > R1 1 2 2200 > R2 1 3 2200 > > .ac dec 100 1 100meg > .plot ac vdb(out) xlog > .end
The error is that the node "out" is only connected via a capacitor to node "3", this will cause spice to fail since there is no way to perform a DC analysis and calculate the operating point on node "out". If you really don't want a load on node "out", you must still add a resistor to ground to support the DC analysis (which is always done first even though this is an AC analysis). Here's the corrected netlist (you were close!): Filter Net Vb 1 0 DC 4.5 Vin in 0 DC 4.5 AC 4.5 C1 in 2 22N C2 2 3 22N C3 3 out 22N R1 1 2 2200 R2 1 3 2200 R3 out 0 10MEG .ac dec 100 1 100meg .plot ac vdb(out) xlog .end Daniel
