HW2-ECE 2280 control system+ analog electronics/micro electronics

1

ECE2280 Homework #2

Use the following equation for problem 1 and 2:

5,000( 1,000) ( )

( 100)( 10) s

H s s s

+ =

+ + 1. (a) Plug in values of ω from 0.1 to 105 rad/sec. Plot this graph of dB vs ω. (Convert Volts/Volts to dB)

(b) Sketch the Bode plots using a straight-line approximation (procedures described in class). 2. (a) Use Matlab to obtain the Bode Plot.

(b) Compare the graphs from 1(a), 1(b), and 2(a). What differences do you see?

3. (a) Sketch the Bode plots for the equation below using a straight-line approximation (procedures described in class).

(b) Use Matlab to obtain the Bode Plots.

(c) Compare the two sketches.

2

2,000( 100)( 1,000) ( )

( 5,000) s s

H s s s + +

= +

4. (a) Sketch the Bode plots for the equation below using a straight-line approximation (procedures described in class).

(b) Use Matlab to obtain the Bode Plots.

(c) Compare the two sketches.

H(s) = ( )

6 2

2 1 10 10 ( 1 ) x s

s s k+ +

5. (a) Sketch the Bode plots for the equation below using a straight-line approximation (procedures described in class).

(b) Use Matlab to obtain the Bode Plots.

(c) Compare the two sketches.  

𝐻 𝑠 = 100𝑘 ⋅ 𝑠

𝑠 + 1 𝑠 + 1𝑘

2

6. Assume all diodes are identical and have VDO=0.7V. Use the constant voltage drop method. Verify that your assumption for the diode operation(i.e. on or off) are correct. Find the following making sure you find the correct operation of the diodes. Show all of your work.

a) State your assumptions (diode is on/off) b) The current ID1 c) The current ID2 d) The voltage Vo e) Verification to prove your assumptions for the diodes

are correct.

7. Assume all diodes are identical and have VDO=0.7V, n=1, and VT=25mV. Use the constant voltage drop method. Verify that your assumption for the diode operation(i.e. on or off) are correct. Find the following making sure you find the correct operation of the diodes. Note that the current source is NOT ideal and has a 1V voltage drop across it.

a) State your assumptions (diode is on/off). b) The current ID1 c) The current ID2 d) The voltage Vo e) Your verification to prove your assumptions for the

diodes are correct.

8. Use the circuit from problem 7: If there is noise on the +10V supply of ± 1V, what is the total value for ID1 (the AC current through diode, D1). {Hint: remember to use the AC model for the diode}

9. Assume all diodes are identical and have VDO=0.7V, n=5, and VT=25mV. Use the constant voltage drop method. Verify that your assumption for the diode operation(i.e. on or off) are correct. Find the following making sure you find the correct operation of the diodes.

f) State your assumptions (diode is on/off). g) The current ID1 h) The current ID2 i) The voltage Vo j) Verification to prove your assumptions for the diodes

are correct.

10. Using the circuit from problem 9. If there is noise on the +10V supply of ± 1V, what is the total value for ID2 (the AC current through diode, D2). {Hint: remember to use the AC model for the diode}