again: SPICE modeling Dual Transistors for NIC Inductors
- Ciao Chris,
I have set the same values of your SPICE_circuit simulation just for computing the actual frequency response in two cases of interest, using 2N3904 and 2N2222 transistors. It seems that the bandwidth is limited to frequencies between 100KHz and 500-600KHz where the first resonance occurs (see the "continuous line" impedance reaching its minimum in the 2N2222 circuit model while the "broken line" of phase is abruptly changing of 180°. NOTE that also in the 2N3904 circuit model you get anyway this abrupt phase change of 180°)
I will try further freq.response simulations using different values of primary/secondary inductances of transformers
Find enclosed my results in PDF, together with the "LTSpice model" of 2N2222 circuit. Your comments and valuable suggestions are welcome !
Warmest ciao ! Roberto
Kindly see the FILES section for getting these simulation results
--- In email@example.com, "Chris Trask" <christrask@...> wrote:
> > I have just created a LTSpice simulation using two 2N2222 transistorsLet
> > know your comments and suggestions
> What bias voltage and current are you using?
> Looks like the solid line is signal current and the dashed line is
> If you place a 5-ohm resistor in series with the signal source you
> should see better results. My simulations showed this impedance
> to be close to ideal.