Design and Verify the operation BCD ripple counter using JK flip-flops

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Aim

To study, design and Verify the operation BCD ripple counter using JK flip-flops.

Learning Objectives

  1. To understand the behavior and demonstrate the operation of BCD ripple counter using JK flip-flops.
  2. To apply knowledge of the fundamental gates to create truth tables.
  3. To develop digital circuit building and troubleshooting skills.
  4. To understand key elements of TTL logic specification or datasheets.

IC Used

For To Design and Verify the operation BCD ripple counter using JK flip-flops:
IC NumberIC Name
74LS76Dual Master-Slave J-K Flip-Flops with Clear, Preset, and Complementary Outputs
74LS00Quad 2-input NAND Gates

Circuit Tutorials:

Procedure

  1. Place the IC on IC Trainer Kit.
  2. Connect VCC and ground to respective pins of IC Trainer Kit.
  3. Implement the circuit as shown in the circuit diagram.
  4. Connect the inputs to the input switches provided in the IC Trainer Kit.
  5. Connect the outputs to the switches of O/P LEDs
  6. Apply various combinations of inputs according to the truth table and observe the condition of LEDs.
  7. Note down the corresponding output readings for various combinations of inputs.
  8. Power Off Trainer Kit, disconnect all the wire connections and remove IC's from IC-Base.

Theory

BCD Counter - ​ Digital counters count upwards from zero to some pre-determined count value on the application of a clock signal. Once the count value is reached, resetting them returns the counter back to zero to start again.

A counter which resets after ten counts with a divide-by-10 count sequence from binary 0000 (decimal “0”) through to 1001 (decimal “9”) is called a “binary-coded-decimal counter” or BCD Counter for short and a MOD-10 counter can be constructed using a minimum of four toggle flip-flops. BCD Counter is a devices that goes through a sequence of ten states when it is clocked and returns to 0 after the count of 9.BCD Counter is a devices that goes through a sequence of ten states when it is clocked and returns to 0 after the count of 9.

A BCD counter counts in a sequence of ten and then returns back to zero after the count of nine. Obviously to count up to a binary value of nine, the counter must have at least four flip-flops within its chain to represent each decimal digit. It is called a BCDcounter because its ten state sequence is that of a BCD code and does not have a regular pattern, unlike a straight binary counter.

BCD Counter State Diagram

A decade counter has four flip-flops and 16 potential states, of which only 10 are used and if we connected a series of counters together we could count to 100 or 1,000 or to whatever final count number we choose.

BCD counters follow a sequence of ten states and count using BCD numbers from 0000 to 1001 and then returns to 0000 and repeats. Such a counter must have at least four flip-flops to represent each decimal digit, since a decimal digit is represented by a binary code with at least four bits giving a MOD-10 count.

Block Diagram

Precautions

  1. Make the connections according to the IC pin diagram.
  2. The connections should be tight on trainer kit.
  3. The Vcc and ground should be applied carefully at the specified pin only.

Conclusion

We have learned all the Design and Implementation of BCD ripple counter using JK flip-flops.

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