![edge triggered flip flop timing diagram edge triggered flip flop timing diagram](https://learnabout-electronics.org/Digital/images/D-Type-timing-01.gif)
This feedback circuit is simply a NAND gate whose inputs are the outputs Q of those flip flops whose output Q = 1 at the count N. Along with flip flops, a feedback gate is added so that at count N all the flip flops get reset to zero. The number of flip flops n to be used in this design are chosen in such a way that 2 n > N where N is the count of the counter. Such a counter is called Divide by N counter. But by modification, we can make ripple counter to count the value which cannot be expressed as a power of 2. So, to count values which are not powers of 2 is not possible with the circuitry that we have seen till now. So, D flip flop is not considered for construction of Ripple Counters. So, the waveform of D0-flip flop will always stay 1, which is not useful for counting. But according to truth table when D value is 1 it stays on 1 until D value is changed to 0. When the clock pulse undergoes the transition from 1 to 0 the flip flop should change the state. So, when a used as Ripple counter D flip flop has initial value as 1. This condition is satisfied by only T and JK flip flops.įrom the truth table of D flip flop, it can be clearly seen that it doesn’t contain the toggling condition. When it comes to selecting a Flip Flop for Ripple counter designing an important point to be considered is that the flip flop should contain a condition for toggling of states. 4 bit Ripple Counter using JK Flip Flop 4 bit Ripple Counter Timing Diagram 4 bit Ripple Counter Using D Flip Flop Below the circuit diagram and timing diagram are given along with the truth table. In 4-bit ripple counter, n value is 4 so, 4 JK flip flops are used and the counter can count up to 16 pulses. The output of Q2 is the MSB.Ĥ-bit Ripple Counter Using JK Flip flop – Circuit Diagram and Timing Diagram So, when Q1 goes from 1 to 0 transitions, the state of Q2 is changed. Here the output waveform of Q1 is given as clock pulse to the flip flop J2K2.
![edge triggered flip flop timing diagram edge triggered flip flop timing diagram](https://cse.unl.edu/~jfalkinburg/cse_courses/2020/436/lecture/img/lecture10-7.gif)
Binary Ripple Counter Using JK Flip Flop 3 bit Ripple Counter Timing Diagram The circuit diagram and timing diagram are given below. As here ‘n’ value is three, the counter can count up to 2 3 = 8 values. In the 3-bit ripple counter, three flip-flops are used in the circuit. From the timing diagram, we can observe that the counter counts the values 00,01,10,11 then resets itself and starts again from 00,01,… until clock pulses are applied to J0K0 flip flop.ģ-bit Ripple counter using JK flip-flop – Truth Table/Timing Diagram Note that the output values of Q0 are considered as LSB and Q1 are considered as MSB. Here don’t consider the above clock pulse, only follow the waveform of Q0. So, as we can see in the timing diagram when Q0 goes transition from 1 to 0 the state of Q1 changes. The process continues for all pulses of the clock.Ĭoming to the second flip flop, here the waveform generated by flip flop 1 is given as clock pulse. As the JK values are 1, the flip flop should toggle. Flip-flop stays in the state until the applied clock goes from 1 to 0. Timing Diagram of Binary Ripple Counterįrom the timing diagram, we can observe that Q0 changes state only during the negative edge of the applied clock. The timing diagram of the binary ripple counter clearly explains the operation. at the transition 1 to 0 of the clock pulse. As we have applied a high voltage to all the JK inputs of flip-flops they are at the state 1, so they must toggle the state at the negative going end of the clock pulse.
![edge triggered flip flop timing diagram edge triggered flip flop timing diagram](http://www.cecs.uci.edu/~gajski/eecs31/homeworks/images/hw5/6.2.answer.gif)
This condition is used in ripple flip flop. So, according to the Truth table, when both the inputs are 1 the next state will be the complement of the previous state. The functioning of the counter can be easily understood using the Truth Table of JK flip flop.
![edge triggered flip flop timing diagram edge triggered flip flop timing diagram](https://files.transtutors.com/book/qimg/14526ee5-ebff-4b86-b879-9d26e37dc192.png)
Here the output Q0 is the LSB and the output Q1 is the MSB bit. From the figure, it can be observed that the output Q0 of the first flip flop is applied as a clock pulse to the second flip flop. The symbol for the clock pulse indicates a negative triggered clock pulse. JK inputs of flip flops are supplied with high voltage signal maintaining them at a state 1. Here two JK flip flops J0K0 and J1K1 are used. The circuit arrangement of a binary ripple counter is as shown in the figure below. While choosing the type of flip-flop it should be remembered that Ripple counters can be designed only using those flip-flops which have a condition for toggling like in JK and T flip flops. As here n value is 2 we use 2 flip-flops. Let us look at the working of a 2-bit binary ripple counter to understand the concept.Ī binary counter can count up to 2-bit values. Based on the number of flip flops used there are 2-bit, 3-bit, 4-bit…. The working of the ripple counter can be best understood with the help of an example. Ripple Counter Circuit Diagram and Timing Diagram