1.
Introduction
2.
What is T Flip Flop?
3.
Construction of T Flip Flop
3.1.
Using SR Flip-Flop
3.2.
Using D Flip-Flop
3.3.
Using JK Flip Flop
4.
Truth Table of T flip flop
5.
Characteristic Table of T Flip Flop
6.
Excitation Table of T Flip Flop
7.
FAQs
8.
Key Takeaways
Last Updated: Mar 27, 2024

# T Flip Flop

## Introduction

Flip-flops continue to maintain their state until they are triggered by an input pulse. A trigger causes the flip-flop outputs to change state in accordance with defined rules and remain in those states until the next trigger. A flip-flop circuit can have several different types of designators, including T Flip flop, SR Flip FlopJK Flip Flop, and D Flip Flop. Let's discuss the T Flip Flop in this blog.

## What is T Flip Flop?

Its defining characteristic is its ability to change its output state. The T Flip-Flop is a synchronous device. You switch from one state (high) to the other state (low) when you toggle.

T flip-flops are edge-triggered devices. It is also named toggle flip flop because of its toggling capability. JK flip-flops are modified versions of this device. When we connect J and K inputs, we create a T input. That's why a T flip flop is also known as a JK flip flop with a single input.

## Construction of T Flip Flop

T flip-flops can be constructed the simplest of all with a JK flip-flop. It consists of two inputs, J and K, connected. The logic circuit of a T flip–flop is given below:

We can design a T Flip Flop with the help of three methods:

• SR Flip-Flop
• D Flip-Flop
• JK Flip-Flop

### Using SR Flip-Flop

You can construct it by feeding AND gates to NOR gates SR latches. In each AND gate, the input is fed back with the output.

To make this work, connect S to the output of a two-input AND gate, which is provided by input T. The R input should now be connected to the output of a two-input AND gate which is provided by T input.

### Using D Flip-Flop

The previous state of O is the XOR with the input T. Next state of O is given at the input D.

The state will remain the same when T=0, D=O at every positive edge.

T=1, D=O, and both remain unchanged during the positive edge clock.

At T=0, the state is retained, but when T=1, it is toggled.

### Using JK Flip Flop

As shown below, we can create a logic circuit for a single bit toggle flip-flop by connecting the J and K data inputs. The common point at the connection point between the two inputs is named T.

## Truth Table of T flip flop

Truth tables illustrate how an output of a logic circuit responds to varying combinations of inputs. It is necessary to set the clock signal high to toggle the output. No matter how high or low the input signal is, the output remains the same when the clock is set low. The clock signal must be high to change the output condition.

Here is the truth table for the T Flip flop in reference to the JK flip flop.

Case 1: Now, if the clock is low(0), then the flip flop will not function, which is why the state will be stored, which means that whatever the value of T, our output will be On(memory).

Case 2: As long as the clock is set to high(1), then J in this scenario will be 0, and K will be 0 as well, so the output will be On whenever this occurs.

Case 3: A toggle action will happen when the clock is high(1) and J = 1, K = 1, which is the case when the clock is high(1) and J = 1, K = 1.

## Characteristic Table of T Flip Flop

The Characteristics Table identifies the next state of the flip-flop given the current state and input. Characteristic table can only be derived from the truth table:

In this, there is a single output, i.e., O(n+1)(next state), which is dependent upon the On(present state) as well as the input. A single output is generated, called O(n+1)(next state), which is determined by inputs and the present state.

So we have concluded that:

O(n+1) = T’O + TO’

O(n+1) = T XOR O

O(n+1) = T ⊕ O

## Excitation Table of T Flip Flop

An Excitation Table defines flip-flop input variables based on the current and next states. Excitation table can only be calculated if you have the characteristic table.

• The excitation input T = 0 is required for the state transition from On = 0 to O(n+1) = 0.
• When On = 0 and On+1 = 1, the input required for excitation is T = 1.
• For input T = 1, the state transit from On = 1 to O(n+1) = 0.
• When T=0, the state transition is from On = 1 to O(n+1) = 1.FAQ’s

## FAQs

1. Write some applications of T Flip Flop.
Some applications are:
→ In addition to their use in binary counters, they are also used in shift registers.
→ These circuits divide the frequency of periodic waveforms.
→ A Flip-Flop can be used as a digital counter, counting pulses or events.