Task 4.7.1: Prelab Questions
Please complete the following tasks assuming VDD=5V and VSS=-5V. Use the Vth and kn values you measured in experiment 3. For kn, use the value for when VGS=2.5V. Assume λ=0.
Refer to the circuit in figure 4.9 for the following questions.
a) Derive an expression for VGS1 and VGS2 in terms of IREF.
b) Derive an expression for VDS2 in terms of IOUT.
c) Calculate the value of IREF that causes VGS2-VTH=VDS2.
d) Explain what happens if IREF is increased beyond the value found in step 1c.
Figure 4.9: Simple current mirror with a load resistor.
Pick R1, R2, RD, and IBIAS in figure 4.7 on page 41 to achieve Av=-4, Vout,dc ≈ 1V and Vout,min ≈ -1V using Q1, Q2, and Q3. Pick R1 and R2 such that R1||R2 > 100kΩ. This design can be done using equations (4.3) and (4.9) to (4.11).
Task 4.7.1: Prelab Questions
Please complete the following tasks assuming Vpp=5V and Vss=-5V. Use the Vth and kn values you measured in experiment 3. For kn, use the value for when VGS=2.5V. Assume λ=0.
Refer to the circuit in figure 4.9 for the following questions.
a) Derive an expression for VGSI and VGS2 in terms of IREF.
b) Derive an expression for PS in terms of IOUT.
c) Calculate the value of IREF that causes VGS2-VTH=VDS2.
d) Explain what happens if IREF is increased beyond the value found in step 1c.
Figure 4.9: Simple current mirror with a load resistor.
Pick R1, R2, RP, and IPAS in figure 4.7 on page 41 to achieve Av=4, Vout,dc ≈ 1V and Voutmin ≈ -1V using Q1, Q2, and Q3. Pick R and R such that R1||R2 > 100kΩ. This design can be done using equations (4.3) and (4.9) to (4.11).
Measured Vth=0.622V Measured Kn=0.763mA/V^2
