Voltage divider bias circuit | Dept of ECE | ANITS

Voltage divider bias circuit and its analysis is discussed

1. Voltage divider bias circuit ANIL PRASAD DADI/ECE/ANITS

2. Problem #1 Assume that a Si transistor with β =200, V BE =0.7V, V CC =15V and R 1 =34K Ω , R 2 =5.9K Ω , R c =1K Ω , R E =510 Ω is used in voltage divider bias circuit. Find the bias point. ANIL PRASAD DADI/ECE/ANITS

3. Problem #2 Assume that a Si transistor with β =100 and V BE =0.7V is used in voltage divider bias circuit as shown below. Find the bias point ANIL PRASAD DADI/ECE/ANITS

4. Problem #3 Assume that a Si transistor with β =50, V BE =0.6V, V CC =22.5V and R C =5.6K Ω is used in voltage divider bias circuit. It is desired to establish a Q-point at V CE =12V, I C =1.5mA and a stability factor of S≤3. Find R E ,R 1 ,R 2 ANIL PRASAD DADI/ECE/ANITS

5. Problem #3 Solution Step 1: Find R E Apply KVL around CE loop ANIL PRASAD DADI/ECE/ANITS

6. Problem #3 Solution Step 2: Find R TH and V TH ANIL PRASAD DADI/ECE/ANITS

7. Problem #3 Solution Step 3: Find R 1 and R 2 ANIL PRASAD DADI/ECE/ANITS

8. Problem #4 Assume that a Si transistor with β =50, V BE =0.6V, V CC =10V and R C =3.5K Ω is used in voltage divider bias circuit. It is desired to establish a Q-point at V CE =5V, I C =1mA and a stability factor of S≤10. Show the circuit diagram with all the components values. ANIL PRASAD DADI/ECE/ANITS

9. Problem #5 Assume that a Si transistor with β =99, V BE =0.6V, V CC =12V and R C =2.2K Ω is used in voltage divider bias circuit. It is desired to establish a Q-point at V CE =5V, I C =2mA and a stability factor of S≤10. Show the circuit diagram with all the components values. ANIL PRASAD DADI/ECE/ANITS

10. V B Problem #6 Assume that a Si transistor with β =100 and V BE =0.7V Determine the bias point ANIL PRASAD DADI/ECE/ANITS

11. V B Problem #6 solution ANIL PRASAD DADI/ECE/ANITS

12. Problem #6 solution ANIL PRASAD DADI/ECE/ANITS

13. Problem #6 solution ANIL PRASAD DADI/ECE/ANITS

14. Problem #7 Assume that a Si transistor with β =200 and V BE =0.7V Determine the bias point ANIL PRASAD DADI/ECE/ANITS

15. Problem #7 ANIL PRASAD DADI/ECE/ANITS

16. Problem #7 ANIL PRASAD DADI/ECE/ANITS

17. Problem #8 Assume that a Si transistor with β =∞, V BE =0.7V, and V CC =3V is used in voltage divider bias circuit shown below. Determine the required value of R2(in K Ω ) to produce I C =1mA. V B ANIL PRASAD DADI/ECE/ANITS

18. Problem #8 Solution Given β =∞ I C =I E ( since I B =0) V B ANIL PRASAD DADI/ECE/ANITS