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Electrical Engineering

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1. This is a small-signal problem built up towards a transfer function. Suppose the BJTs drawn have g, =
1 mS when [, = 1 mA. Additionally, 2, will be different in each part.
Vec = SV Vour
Re = 5 kQ
Vout
=77?
Vin R, =???
Vin
LL Vour
Vin
(a) Derive Ay for this circuit assuming R, = oo, draw the transfer function on the first plot above,
and label Ay. Point out where the BIT is in saturation mode.
(b) Derive Ay, for this circuit assuming R,; = 50, draw the transfer function on the second plot
above, and label Ay.
(c) For both plots, draw the limits of the peak-to-peak voltage regions for Vi, Voy as pairs of vertical
and horizontal lines, respectively. Assume our output signal has peak-to-peak of roughly 200 mv.

2. This is a small-signal problem built up towards a transfer function. Suppose the MOSFETs drawn have
Gm = 1mS when V;>5 = 2.5V, and V,, = 0.5V.
Vop = 5 V Vour
Vin —
Vout
Rs =5kQ R, =???
| Vin
~ ~ Vour
Vin
(a) Derive Ay for this circuit assuming R, = oo, draw the transfer function on the first plot above,
and label Ay. Explain whether you expect clipping or not.
(b) Derive Ay, for this circuit assuming R,; = 50, draw the transfer function on the second plot
above, and label Ay.