Digital Electronics (commonly called DE) is a branch of Electronics that deals with digital circuits and systems. The digital systems work on Binary Signals which are represented using Binary Digits (i.e., 0 and 1). In Digital Electronics, information at the basic level is stored using the Flip Flops. Flip Flops are essential building blocks that are used to store 1 bit of binary information. Let us learn more about this versatile component along with the jk flip flop truth table and its working.
What is a JK Flip-Flop?
The JK flip-flop is a sequential logic circuit that can store one bit of binary information. It is a modification of the SR flip-flop with some added features that make it more versatile. The JK flip-flop is named after its inventor Jack Kilby, who was a Texas Instruments engineer and a co-inventor of the integrated circuit. The JK flip-flop is a type of edge-triggered flip-flop, which means that its output changes only when a clock pulse is applied to its clock input.
Block Diagram of JK Flip Flop
This is the block diagram of a JK Flip Flop. It consists of two inputs J (set) and K (reset), a clock input, and two outputs denoted as Q and Q’.
Here the clock input is used to trigger the flip-flop and change its state. Q is the main output of the JK Flip Flop, and Q’ is the complement of the output Q.
Circuit Diagram of JK Flip Flop
The internal construction of the JK flip-flop can be explained using a NAND gate latch. A NAND gate is a logic gate that produces an output that is the complement of the logical AND of its inputs. The JK flip-flop is constructed using two NAND gates, as shown in the figure below.
The inputs J and K are connected to the inputs of the first NAND gate, while the outputs of the first NAND gate are connected to the inputs of the second NAND gate. The output of the second NAND Gate is connected to the input of the first NAND gate, also forming a feedback loop (that is why they are called sequential circuits). The Input Clock is connected to both of the NAND gates and its signal determines when the output of the flip-flop changes.
JK Flip Flop Truth Table
The JK Flip Flop Truth Table is given below:
In the above truth table, Q(n) represents the output of the flip-flop at time n, while Q(n+1) represents its output at time n+1.
When J and K are both low (0), the output of the flip-flop remains the same as its previous state i.e.,
Q(n) = Q(n+1)
When K is high (1) and J is low (0), the output of the flip-flop is reset to 0. When J is high (1) and K is low (0), the output of the flip-flop is set to 1.
When both J and K are high (1), the output of the flip-flop toggles between its current state and its complement i.e.,
Q(n+1) = Q'(n)
Timing Diagram of JK Flip Flop
With the help of the above truth table, we can easily write the output equation of the JK Flip Flop as
Below is the timing diagram of the JK Flip Flop.
Applications of JK Flip-Flop
JK Flip-Flop has several Applications in the field of Digital Electronics. Some of the Applications of the JK Flip Flop are discussed below in brief.
- Frequency Division: By connecting the JK flip flop’s output to its clock input, it can be used used as a frequency divider. As the flip-flop toggles between states, it produces a square wave at half the clock input frequency. We can make square waves with lower frequency by cascading multiple JK flip-flops.
- Shift Registers: The JK flip-flop may be used to construct shift registers, which store and shift binary data. We can shift binary data from one flip-flop to another by connecting multiple JK flip-flops in a chain. Shift registers are used extensively in digital communication systems, serial data transfer, and data storage devices.
- Counters: The JK flip-flop can be used to build counters that count the number of clock pulses. We can make binary counters that can count up or down by connecting multiple JK flip-flops in a cascade arrangement. Counters are commonly found in digital circuits like timers, frequency synthesizers, and digital clocks.
- Memory Elements: Binary data may be stored in the JK flip-flop when used as a memory element. We design memory devices that can store a vast quantity of binary data by connecting multiple JK flip-flops in a parallel configuration. Memory devices are widely used in computer systems, digital cameras, and mobile phones.
In conclusion, the JK flip-flop is a versatile and essential digital electronics building component. Because of its capacity to toggle its output depends on its present state and the values of its inputs, it is useful for a wide range of applications, including frequency division, shift registers, counters, and memory components. The JK flip-flop truth table and timing diagram show how it responds to clock pulses and input values.
Frequently Asked Questions (FAQs)
Some Frequently Asked Questions on JK Flip Flop are given below.
Ques 1. What is JK Flip Flop full form?
Ans. The JK Flip Flop full form is:
- J – Jack
- K – Kilby
It is named on the name of its inventor, Jack Kilby.
Ques 2. What is a JK flip-flop, and how does it differ from other flip-flops?
Ans. A JK flip-flop is a type of sequential logic circuit that can store one bit of data. It differs from other flip-flops like the D and T flip-flops because it has two inputs: J (set) and K (reset), which can be used to toggle the output of the flip-flop.
Ques 3. What is the difference between a synchronous and asynchronous JK flip-flop?
Ans. A synchronous JK flip-flop has a clock input that controls when the inputs are sampled and the output is updated, while an asynchronous JK flip-flop has inputs that can change the output at any time, regardless of the clock input.
Ques 4. What is the difference between a positive-edge-triggered and negative-edge-triggered JK flip-flop?
Ans. A positive-edge-triggered JK flip-flop changes its output on the rising edge of the clock signal, while a negative-edge-triggered JK flip-flop changes its output on the falling edge of the clock signal.
Ques 5. How can you use a JK flip-flop to implement a memory element?
Ans. By using a JK flip-flop with a feedback loop that feeds the output back to the input, you can create a memory element that can store one bit of data indefinitely.