1. SEQUENTIAL CIRCUITS
Sequential Circuits
Sequential Circuits

2. Two Types of Switching Circuits
Combinational Circuits
Combinational circuits have only input and output. Output depends on input.
Example: AND,OR,NAND,NOR,XOR etc
Sequential Circuits
Sequential circuits have input, present state, next state and output. Next state depends upon present state and input. Output depends upon present state and input
Example: Flip-Flops etc
Sequential Circuits
Sequential Circuits

3. FLIP FLOPS AND THEIR APPLICATIONS1.
Sequential Circuits
Sequential Circuits

4. Sequential Circuits
Sequential Circuits

5. Sequential Circuits
Sequential Circuits

6. Sequential Circuits
Sequential Circuits

7. Sequential Circuits
Sequential Circuits

8. Sequential Circuits
Sequential Circuits

9. When any two out of S,R,T equals 1, we have don’t care
When S = 1, Q+ = 1
When R = 1, Q+ = 0
When T = 1, State changes
When any two out of S,R,T equals 1, we have don’t care
Sequential Circuits
Sequential Circuits

10. Sequential Circuits
Sequential Circuits

11. T- Flip Flop Example 1: Design a modulo-8 binary -up counter using
Modulo 8 counter :
Counts upto 7 . So we need three Flip-flops for
eight states
Sequential Circuits
Sequential Circuits

12. modulo-8 counter
Sequential Circuits
Sequential Circuits

13. modulo-8 counter
Sequential Circuits
Sequential Circuits

14. modulo-8 counter
Sequential Circuits
Sequential Circuits

15. modulo-8 counter
Sequential Circuits
Sequential Circuits

16. T- Flip Flop with input x
Example 2:
Design a modulo-8 binary -up counter using
T- Flip Flop with input x
Modulo 8 counter :
Counts upto 7 . So we need three Flip-flops for
eight states
Sequential Circuits
Sequential Circuits

17. modulo 8 counter with I/p x
Sequential Circuits
Sequential Circuits

18. modulo 8 counter with I/p x
Sequential Circuits
Sequential Circuits

19. modulo 8 counter with I/p x
Sequential Circuits
Sequential Circuits

20. modulo 8 counter with I/p x
Sequential Circuits
Sequential Circuits

21. using SR- Flip Flop without input x
Example 3:
Design a binary decade counter
using SR- Flip Flop without input x
Decade Counter:
Counts up to 9 . So we need four Flip-Flops
for ten states
Sequential Circuits
Sequential Circuits

22. Binary Decade counter
Sequential Circuits
Sequential Circuits

23. Binary Decade counter
Sequential Circuits
Sequential Circuits

24. Binary Decade counter
Sequential Circuits
Sequential Circuits

25. Binary Decade counter
Sequential Circuits
Sequential Circuits

26. Binary Decade counter
Sequential Circuits
Sequential Circuits

27. way specified below, use J-K Flip-Flop.
Example 4:
Design a modulo-8 counter which counts in the
way specified below, use J-K Flip-Flop.
Sequential Circuits
Sequential Circuits

28. TRUTH TABLE: present state next state Sequential Circuits

29. Gray code counter Y3
Sequential Circuits
Sequential Circuits

30. Gray code counter: Y2
Sequential Circuits
Sequential Circuits

31. Gray code counter: Y1
Sequential Circuits
Sequential Circuits

32. Design a T-Flip-Flop using S-R Flip-Flop
Example 5:
Design a T-Flip-Flop using S-R Flip-Flop
Sol:
Sequential Circuits
Sequential Circuits

33. T Flip flop using S-R flipflop
Sequential Circuits
Sequential Circuits

34. Design a J-K Flip Flop using S-R Flip Flop
Example 6:
Design a J-K Flip Flop using S-R Flip Flop
Sol:
Sequential Circuits
Sequential Circuits

35. J-K Flip Flop using S-R Flip Flop
Sequential Circuits
Sequential Circuits

36. Design a sequential circuit given below using J-K FlipFlop
Example 7:
Design a sequential circuit given below using J-K FlipFlop
Sequential Circuits
Sequential Circuits

37. Truth Table: I/p Present st. Next state o/p Sequential Circuits

38. Design of Seq. Circuit
Sequential Circuits
Sequential Circuits

39. Design of Seq. Circuit
Sequential Circuits
Sequential Circuits

40. Design of Seq. Circuit
Sequential Circuits
Sequential Circuits

41. Design of Seq. Circuit
Sequential Circuits
Sequential Circuits

42. Design a binary modulo-5 counter using SRT- Flip Flop with input x
Example 8:
Design a binary modulo-5 counter using SRT- Flip Flop with input x
Modulo-5 Counter:
Counts up to 4 . So we need three Flip-Flops for five states
Sequential Circuits
Sequential Circuits

43. Binary Modulo-5 counter
STATE TABLE
Sequential Circuits
Sequential Circuits

44. Binary Modulo-5 counter
Sequential Circuits
Sequential Circuits

45. Binary Modulo-5 counter
Sequential Circuits
Sequential Circuits

46. Binary modulo-5 counter
Note: Here S’and C’ stands for the compliment value of the corresponding cells
in the S and C K-maps
Assume T’ =
So S’ and C’ comes out to be
Sequential Circuits
Sequential Circuits

47. Binary Modulo-5 counter
Sequential Circuits
Sequential Circuits

48. Binary modulo-5 counter
Assume T’ =
So S’ and C’ comes out to be
Sequential Circuits
Sequential Circuits

49. Binary modulo-5 counter
Sequential Circuits
Sequential Circuits

50. Binary modulo-5 counter
Assume T’ = 1
So S’ and C’ comes out to be
0 and 0
Sequential Circuits
Sequential Circuits

51. G = 0 Q+ does not respond G = 1 Q+ responds Sequential Circuits

52. T-G Flip Flop Application Equation
This is the Application Equation of the T-G Flip-Flop
Sequential Circuits
Sequential Circuits

53. Design T2 and G2 for a modulo-5 binary up counter
Example 9:
Design T2 and G2 for a modulo-5 binary up counter
Modulo-5 counter:
Counts up to 4 . So we need three Flip-Flops for five states
Sequential Circuits
Sequential Circuits

54. Modulo 5 binary upcounter STATE TABLE
Sequential Circuits
Sequential Circuits

55. Modulo 5 binary upcounter
Sequential Circuits
Sequential Circuits

56. Modulo 5 binary upcounter
Sequential Circuits
Sequential Circuits

57. Modulo 5 binary upcounter
Sequential Circuits
Sequential Circuits

58. Modulo 5 binary upcounter
Sequential Circuits
Sequential Circuits

59. Counts up to 7 . So we need three Flip-Flops for seven states
Example 10:
Design an Octal upcounter(Binary counter) using S-C Flip-Flop using Tabular Method
Octal up counter:
Counts up to 7 . So we need three Flip-Flops for seven states
Sequential Circuits
Sequential Circuits

60. Octal up counter
STATE TABLE
Sequential Circuits
Sequential Circuits

61. Octal up counter
Sequential Circuits
Sequential Circuits

62. Octal up counter
Sequential Circuits
Sequential Circuits

63. Octal up counter
Sequential Circuits
Sequential Circuits

64. RULES TO DERIVE EXCITATION FUNCTION
T- Flip-Flop
Sequential Circuits
Sequential Circuits

65. S-C Flip Flop
Sequential Circuits
Sequential Circuits

66. J-K Flip Flop
Sequential Circuits
Sequential Circuits

67. T-G Flip Flop
Sequential Circuits
Sequential Circuits

68. S-C-T Flip Flop
Sequential Circuits
Sequential Circuits

69. Summary of Rules for all Flip-Flops
Sequential Circuits
Sequential Circuits

70. MODIFIED RULES FOR THE FLIP-FLOPS
Sequential Circuits
Sequential Circuits

71. questions ???
Sequential Circuits
Sequential Circuits