To implement and test the JK Flip-Flop using the 74LS73 IC.
To observe the effect of clock pulses and different input conditions on the flip-flop outputs.
To display the output of the flip-flop using LEDs.
Breadboard
+5V power supply
Variable frequency clock signal
Switches (for inputs)
LEDs (for output indication)
74LS73 JK Flip-Flop IC
Connecting wires
A JK Flip-Flop is a sequential logic circuit that changes state on the application of clock pulses based on its inputs, J (set) and K (reset). The 74LS73 IC contains dual JK Flip-Flops with a negative-edge triggered clock. The truth table of the JK Flip-Flop is as follows:
J|K|Clock|Q(t+1)|
0|0| ↑ | Q(t) |
0|1| ↑ | 0 |
1|0| ↑ | 1 |
1|1| ↑ | Q'(t)|
Where ‘↑’ represents the positive edge of the clock pulse.
+-----+
J --| |-- Q
K --| |
CP'--|> |
R --| |-- Q'
+-----+
J: Set input
K: Reset input
CP: Clock input. Flip flop acts on negative clock edges
R: Enable (Direct Reset)
---------+---------
INPUTS | OUTPUTS
R CP J K | Q Q'
---------+---------
L X X X | L H
H ↓ L L | No change
H ↓ H L | H L
H ↓ L H | L H
H ↓ H H | Toggle
H H X X | No change
---------+---------
H = high level (steady state),
L = low level (steady state),
X = irrelevant,
↓ = high-to-low transition
+-----u-----+
1CP'--|1 o 14|-- 1J
1R'--|2 13|-- 1Q'
1K --|3 12|-- 1Q
Vcc --|4 11|-- GND
2CP'--|5 10|-- 2K
2R'--|6 9|-- 2Q
2J --|7 8|-- 2Q'
+-----------+
74HC73 Dual JK Flip Flop
Place the 74LS73 IC on the breadboard.
Connect the Vcc pin to +5V and GND pin to ground.
Connect switches to J and K inputs.
Connect a clock signal to the clock pin of the flip-flop.
Connect output pins Q and Q' to LEDs for visual indication.
Testing the Flip-Flop:
Set different combinations of J and K inputs using switches.
Observe and record the output on LEDs when a clock pulse is applied.
Verify the operation using the truth table.
When J = 0 and K = 0, output remains unchanged.
When J = 0 and K = 1, output resets to 0.
When J = 1 and K = 0, output sets to 1.
When J = 1 and K = 1, output toggles on each clock pulse.
This experiment demonstrates the working of the JK Flip-Flop using the 74LS73 IC. By analyzing different input combinations and clock pulses, we can observe how flip-flops store and change state, which is fundamental to digital circuit design.