# Flip Flop Conversion

john August 11, 2018 68 Comments

In this article, let’s learn about flip flop conversions, where one type of flip flop is converted to another type.

For the conversion of one flip flop to another, a combinational circuit has to be designed first. If a JK Flip Flop is required, the inputs are given to the combinational circuit and the output of the combinational circuit is connected to the inputs of the actual flip flop. Thus, the output of the actual flip flop is the output of the required flip flop. In this post, the following flip flop conversions will be explained.

• SR Flip Flop to JK Flip Flop

As told earlier, J and K will be given as external inputs to S and R. As shown in the logic diagram below, S and R will be the outputs of the combinational circuit.

The truth tables for the flip flop conversion are given below. The present state is represented by Qp and Qp+1 is the next state to be obtained when the J and K inputs are applied.

For two inputs J and K, there will be eight possible combinations. For each combination of J, K and Qp, the corresponding Qp+1 states are found. Qp+1 simply suggests the future values to be obtained by the JK flip flop after the value of Qp. The table is then completed by writing the values of S and R required to get each Qp+1 from the corresponding Qp. That is, the values of S and R that are required to change the state of the flip flop from Qp to Qp+1 are written.

SR Flip Flop to JK Flip Flop

• JK Flip Flop to SR Flip Flop

This will be the reverse process of the above explained conversion. S and R will be the external inputs to J and K. As shown in the logic diagram below, J and K will be the outputs of the combinational circuit. Thus, the values of J and K have to be obtained in terms of S, R and Qp. The logic diagram is shown below.

A conversion table is to be written using S, R, Qp, Qp+1, J and K. For two inputs, S and R, eight combinations are made. For each combination, the corresponding Qp+1 outputs are found ut. The outputs for the combinations of S=1 and R=1 are not permitted for an SR flip flop. Thus the outputs are considered invalid and the J and K values are taken as “don’t cares”.

JK Flip Flop to SR Flip Flop

• SR Flip Flop to D Flip Flop

As shown in the figure, S and R are the actual inputs of the flip flop and D is the external input of the flip flop. The four combinations, the logic diagram, conversion table, and the K-map for S and R in terms of D and Qp are shown below.

SR Flip Flop to D Flip Flop

• D Flip Flop to SR Flip Flop

D is the actual input of the flip flop and S and R are the external inputs. Eight possible combinations are achieved from the external inputs S, R and Qp. But, since the combination of S=1 and R=1 are invalid, the values of Qp+1 and D are considered as “don’t cares”. The logic diagram showing the conversion from D to SR, and the K-map for D in terms of S, R and Qp are shown below.

D Flip Flop to SR Flip Flop

• JK Flip Flop to T Flip Flop

J and K are the actual inputs of the flip flop and T is taken as the external input for conversion. Four combinations are produced with T and Qp. J and K are expressed in terms of T and Qp. The conversion table, K-maps, and the logic diagram are given below.

JK Flip Flop to T Flip Flop

• JK Flip Flop to D Flip Flop

D is the external input and J and K are the actual inputs of the flip flop. D and Qp make four combinations. J and K are expressed in terms of D and Qp. The four combination conversion table, the K-maps for J and K in terms of D and Qp, and the logic diagram showing the conversion from JK to D are given below.

JK Flip Flop to D Flip Flop

• D Flip Flop to JK Flip Flop

In this conversion, D is the actual input to the flip flop and J and K are the external inputs. J, K and Qp make eight possible combinations, as shown in the conversion table below. D is expressed in terms of J, K and Qp.

The conversion table, the K-map for D in terms of J, K and Qp and the logic diagram showing the conversion from D to JK are given in the figure below.

D Flip Flop to JK Flip Flop

##### We recommend:
• Meryl Ann Benild
November 13, 2018

Can u leave the excitation table and truth table of SR , JK , D ,T separately..

• September 21, 2018

Best Helping Materials Regarding with Flip Flop Conversion 🙂

Thank You Sir 🙂

• September 8, 2016

How to convert JK ff to D ff on digital traineer kit?How to convert D ff to JK ff on digital traineer kit?

• September 8, 2016

how to convert JK ff to D ff on digital traineer kit?

• Vidya Bhandari
July 6, 2016

If we are designing the JK flip flop using SR flip flop ,In that case what is the role of K-map in that designing procedure

• Sailendra
November 27, 2015

Very usefull ,but a small mistake is there in jk to d
In d flip-flop when D=1 Q(p+1)=1

• November 15, 2015

thanks sir it is very clear and understandable . i am confuse convert JK flip flop to T flip flop when i solve this the answer of this is comes J=T and K=T zabar but you are answer is different

• Sonny Khlane
November 4, 2015

Can you do the charateristic table for the converted gate? What will be the charatersitic table for ‘JK Flip-flop to T flip-flop’ circuit for example?

• October 28, 2015

still more flip flop conversions must be there

• October 28, 2015

there is mistake in D flip-flop to JK flip-flop

• June 19, 2015

Thank you so much for these flip flop conversions

• aravind
May 18, 2015

there is a mistake in the SR flipflop to JK flipflop where S=(~J)*Qp.

• Daniel Luu
October 7, 2015

I agree, There is AN ERROR. JK —> SR. It is suppose to be S= JQ’

• abhay
January 6, 2016

yeah, encountered the same thing. there’s a mistake there in the first conversion.

• ALOK
April 11, 2015

THANKS

• snehrahul
March 31, 2015

How to convert sr flip flop to t flip flip?

• RAHUL KESHRI
December 18, 2014

In conversion of sr to jk flipflop
Y r we not paring with don’t cares..???
Since we are pairing with don’t cares in each conversion…

Reply me on my mail id its urgent to know…

Thanks

• Navneet Toor
December 6, 2014

• November 28, 2014

this is awsome.it is very helpfull to me for checking my task is correct or not……..thanks a megaton

• Abhi
November 28, 2014

but one mistake is there.in SR toJK flip flop the eqn for s will be S=J*Qp bar .

• Shreya
November 26, 2014

very easily explained.Thanks a lot

• Amit
November 19, 2014

• keshav sharma
November 12, 2014

it is very useful 4 me thanks for u

• Umesh
August 24, 2014

Wonderful explanation. Easy language used. Very easy to learn! Thanks a ton!

May 8, 2014

Its very clear and understandable , thank u so much.

• Rajesh Hanswal
May 6, 2014

It will be S=J*(Q_p)’ in S-R to J-K conversion instead of J’*(Q_p) this error is in the K-Map Solution for S.
Otherwise it is very good content and very useful..
Thanx

• May 1, 2014

it is very useful to me thanks………….

April 20, 2014

These information are very helpful for those who want to know about flip flop. It is wonderful.

• April 11, 2014

This was wonderful. I am going to tell my classmates about it. Our professor just couldn’t seem to explain it this clearly, so this really helped. Thanks!

• March 30, 2014

In the SR Flip Flop to D Flip Flop
there is a mistake in the R K-Map
the term (1) should be “1” not “0”

• sumanti
February 28, 2014

found it helpful for writing exam …
ACTUALLY COYING DURING THE EXAM 😀
KEEP IT UP !!!!!!!

• Tarek Jreidini
December 17, 2013

thank you so much my exam’s in 4 hours i needed this

• Tiago
December 16, 2013

Awesome. Thanks. Althought there’s an error on the JK Flip Flop to D Flip Flop table. Last line. Qp+1 should be 1 and not 0. But the corresponding JK Inputs are correct. This said, everything is good except Qp+1.

• Tarun
December 1, 2013

Thanks A bunch…:-)

• November 28, 2013

• Bharatish Puranik
November 20, 2013

That Was awesome….gracias…

• rahul kumar
October 27, 2013

please try to keep the solution for D-ff to T-ff conversion

• vijay kumar
October 21, 2013

can i have details about D flip flop to SR flip flop using NOR gates only.

• Usman
January 2, 2016

when an SR is clocked it dxnt matter whether its NOR or NAND…. both have same characteristics….

• isabel
October 12, 2013

muy buen contenido …gracias

• Jeny
October 5, 2013

thank u very much…!!
its up to the point and brief.

• September 22, 2013

• JITENDRA KHATIK
August 19, 2013

• Terry
July 26, 2013

Very useful! Thank u very much!

• gyanendra
July 12, 2013

thankyou so much!!!

• Sarang
June 12, 2013

Thank you so much…Saved me 🙂

• MUsa
May 12, 2013

Thanks a lot
This is nice site for digital logic

• Santosh Kumar Patel
April 6, 2013

Thank’s you so much it is good details for digital information. i will com back in your web sites.

• ammar
March 23, 2013

Thanks a lot
I hope if there is a suitable reference (student language not complex teacher language methods) for digital communication and for digital system design ??

• varinder insa
March 6, 2013

its so so interesting & excellent

• Martin
February 14, 2013

This is very interesting…

• alireza
February 14, 2013

thanks

• March 21, 2013

Alireza
I worked in the Postal Service, it had a large training section where we laearned to service electronic equipment. It was located in Norman, Oklament. At the University of Oklahoma. The last equipment I woked on was the Optical Cahriter Reader (OCR) the hardest logic I had to learn was the Master Slave J K Flipflop. I finnaly learned how it worked just before the test that was given every Friday. Well that was the only question I missed on the test. The instructor had a way to change just a little of something different.

• pain
December 30, 2012

thank u 🙂

• jatinder
December 9, 2012

good one and thanks dude for help me for this topic ………

• Arunraj K
December 4, 2012

Thanks a lot. It will help to brush up my skills.

• Arvind
December 3, 2012

Excellent!!!

• Lakshya
November 21, 2012

Perfect !
Now I think i can convert any flip flop to other !
Thanks a lot !

• baiduryakanti majumder
November 7, 2012

the figure in the conversion of jk to d is slightly incorrect …
the last row in the conversion table should be corrected…i feel ….
please comment if i am wrong…

• poi
May 6, 2016

you are correct, the last row should be qp = 1 and qp+1 = 1

• Ilia afshari
August 1, 2016

yes
d=1 Qp=1 Qp+1=1

• farhaan
September 26, 2012

thank you very much.the explanations is quite simple and very easy to understand.please also post on registers.

• LeDinhTan
July 29, 2012

Excellent! Thank you very much.

• Sandip mangukiya
July 23, 2012

very good.explanation is quite simple and fundamentally stupedous

• masoomeh
July 21, 2012

Excellent!
Thank you.

• Romel
April 8, 2012

Thank you very much john. Much needed topics!!

• Rakesh
March 3, 2012

you worked really hard Mr. john. You concentrated upon a very useful topic.

• poki
July 29, 2013

Excellent!
Thank you so much!