Homework 5 Solved - Microelectronic Circuits | ECE 3040, Assignments of Electrical and Electronics Engineering

Download Homework 5 Solved - Microelectronic Circuits | ECE 3040 and more Assignments Electrical and Electronics Engineering in PDF only on Docsity! Homework 1. For the basic transistor circuit below, solve for the Q-point (all three currents and voltages on the transistor) assuming a B=100, an Early voltage, V4=100V, a Viun on=0,7 V for any forward biased Base-cmitter junction and a Vian o: 0.3 V for any forward biased base-collector junction (different duc to lower doping in CB junction): a. Assuming the transistor is biased in cutoff (neglect leakage currents). b. Assuming the transistor is biased in saturation. c. Assuming the transistor is biased in forward active. d. Which assumption is valid? ny BT R2 40k » C2 YeoutDC VoutAc 4 et cr Qs 100GuF Vina ANN | ftp $$$ gprcin ik 1000uF 4 V3 “a e. What value of Is would result in 0.7 V «lve rv M% ca -k F Rs Sam ] 10004 ] _ 100k for the base emitier voltage? f. Determine the voltage gain VoutAC/VinAC. g. Plot VoutDC and VoutAC for a 1 kHZ, ImV VinAC signal. b. Note: While f am not asking for it herein, you should be able to determine, B, &, and Is from the fundamental mat crial parameters.  2. For the circuit below, assume that the transisior is biased in forward active mode and B=255.9 and Is=14.3fA. Note that the Zener diode and R10 together operate in a similar fashion to the circuit assigned in homework 4 and you can neglect the small basc current compared to all other currents. What is the voltage Vout when a) the resistance R,=500 ohms, b) the resistance R}=1000 ohms, c) the resistance R.=2000 ohms. d) for a load resistance RL=500 ohms but with a power supply voltage VDCin=9V and 15 V, c) Explain the function and operation of this “voltage regulator power supply” circuit. Note: in reality , a larger “pass transistor” (as is it called in this type of application would be typically used. A 2N2222 was used only for convenience. 0N2222 Vout Ra . Wire 4 10 a } i me f we = AM prnnnn $4 Rioad 600 1. ‘ bs gy BIN —-—$4— 3. Assume Forward active mode bias and find the current flowing in R3 and compare it to the current flowing in R2 for this “current Mirror” circuit. What sets these currents (i.c. how can we change them)? The B=416.4 and Is=6.734fA. Note: it may be helpful to consider the simplified Ebers Moll model only for determining the collector currents in the two transistors but otherwise use the Beta/CVD method. What happens to the currents if R3 is replaced with a 5% resistor? Why? Note this circuit is often used to implement a current source, ve R2 19K ty de i me Kk Ele J 7 a7Na904 ; OaNgava Re Ry ,  4, Assume forward active mode and solve the Q-point for the following “Darlington configuration” and determine the total current flowing in R3 compared with the base current flowing in Q7. Tye 2N3906 tpavoiotop Nac a P=180.7 and Is=1.41fA, Sometimes this is called a “Super Beta” transistor configuration. Why is such a term applicable? Ra s 51k VoutDC Q2N3906 or To i O68 s @2Nae08 Ra 2 10k RS j 22K 0