So far, we have treated transistors as ideal switches An ON transistor passes a finite amount of current – Depends on terminal voltages – Derive current-voltage (I-V) relationships Transistor gate, source, drain all have capacitance – I = C (∆V/∆t) - ∆t = (C/I) ∆V – Capacitance and current determine speed .MOS Capacitor Gate and body form MOS capacitor V Vt + inversion region depletion region .Terminal Voltages Vg Mode of operation depends on Vg, Vd, Vs + + – Vgs = Vg – Vs Vgs Vgd – Vgd = Vg – Vd Vs Vd – Vds = Vd – Vs.
