In introductory texts, the BJT is said to be a unilateral device. I think it means that the base current is only a function of Vbe; and Vbe is not function of Vce and Ic(?) Is the following BJT model unileteral or bileteral?

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In other words, according to the above model, is the base current or Vbe function of any output parameters like Vce or Ic?

  • \$\begingroup\$ That's a small-signal version (using derivatives) and is useless for large-scale results. The large-scale models (lacking Early Effect \$r_o\$, though) are here. If you focus on active mode and take the deriviative, you'll get the linearized hybrid-\$\pi\$. But it's only valid close-by around a specific operating point. \$\endgroup\$ – jonk Mar 2 at 22:03
  • \$\begingroup\$ I see but Im asking only about the approximate model in the question. Is that model unileteral? \$\endgroup\$ – pnatk Mar 3 at 0:55
  • \$\begingroup\$ Well, if I felt I understood the exact question I might try and offer a suggestion. But I don't feel as though I do. So I'm not sure which direction to head. That said, do you understand how a current mirror works? \$\endgroup\$ – jonk Mar 3 at 1:45

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