1. ENEE 303 6th Discussion

2. Contents MOSFET differential pair (discussion 5) Y matrix of BJT
Homework problems

3. Differential Pair: MOSFET
I in terms of (vb1-vb2)

4. Small-Signal Operation of the MOS Differential Pair
Neglect channel modulation
Because of symmetry, the common source connection acts as virtual ground

5. Y Matrix of BJT
I in terms of (vb1-vb2)

6. Y Matrix of BJT
𝒊𝒃 𝒊𝒄 𝒊𝒆 = 𝒈𝝅+𝒔𝑪𝝅, 𝟎, −𝒈𝝅−𝒔𝑪𝝅 𝒈𝒎, 𝒈𝒐, −𝒈𝒎−𝒈𝒐 −𝒈𝝅−𝒈𝒎−𝒔𝑪𝝅, −𝒈𝒐, 𝒈𝝅+𝒈𝒎+𝒈𝒐+𝒔𝑪𝝅 𝒗𝒃 𝒗𝒄 𝒗𝒆
I in terms of (vb1-vb2)

7. Y Matrix of BJT: HW6 Problem1
Assume a properly biased transistor working linearly with small signals.
a) For the grounded base transistor give the admittance matrix with port-1 seen as emitter to base and port-2 as collector to base.
b) From that give the input admittance seen at the emitter to ground when loaded at the collector to ground by yL(s).
c) Find the Thevenin’s equivalent seen from collector to base when fed at port-1 by a voltage source, vi, in series with a resistor of conductance Gi.
I in terms of (vb1-vb2)

8. CMOS bidirectional current mirror
I in terms of (vb1-vb2)

9. OTA with feedback
I in terms of (vb1-vb2)

10. Thevenin’s Equivalent Circuit
Find the small signal Thevenin’s equivalent seen looking between the output and ground of the following circuit.
Assume complementary transistors biased at collector currents of 5ma, Early voltages of 20V, Cπ=1pFd and Cμ=0.
I in terms of (vb1-vb2)