0 votes 0 votes An AB flip-flop (FF) is constructed from a JK-FF as shown in the figure. The expression for the next state J=AB’+BA’ and K=A+B characteristic equation of JK FF Qn+1=JQn’+KQn Digital Logic made-easy-test-series digital-logic digital-counter + – Shivam Kasat asked Jan 6, 2019 • edited Mar 4, 2019 by Rishi yadav Shivam Kasat 761 views answer comment Share Follow See all 11 Comments See all 11 11 Comments reply Show 8 previous comments Shivam Kasat commented Jan 9, 2019 reply Follow Share No brother, your answer is right. I am getting the same answer while solving using truth table but doubt is why am I not getting the same answer using characteristic equation. @Prateek Raghuvanshi 0 votes 0 votes Prateek Raghuvanshi commented Jan 9, 2019 reply Follow Share @ Shivam Kasat, because you are using wrong expression for $Q_{n+1}$.it should be $Q_{n+1}=J(\sim Q_{n})+(\sim K)Q_n$ 0 votes 0 votes Shivam Kasat commented Jan 9, 2019 reply Follow Share @Prateek Raghuvanshi Thanks a lot. 1 votes 1 votes Please log in or register to add a comment.