Sequential Circuits
All the digital systems designed and analyzed so far are based upon combinational logic, where the output levels at any instant of time depend only upon the levels present at the inputs at that time. Such systems are said to be memoryless systems. However, there are many applications in which digital outputs are required to be generated in accordance with the sequence in which the input signals are received, which cannot be accomplished using combinational circuits. These applications require outputs to be generated; they are not only dependent on the level present at the inputs at that time but also on the state of the circuit, i.e., on the prior input level conditions. The past history is provided by feedback from the output back to the input. Thus, sequential circuits are made up of combinational circuits and memory elements.
The figure shows the block diagram of a sequential circuit. It consists of a combinational circuit, which accepts digital signals from external inputs and from the outputs of memory elements connected in a feedback path and generates signals for external outputs and for the inputs to the memory element. The table shows the comparison between combinational and sequential circuits.
Dear Aspirants,
Your preparation for GATE, ESE, PSUs, and AE/JE is now smarter than ever — thanks to the MADE EASY YouTube channel.
This is not just a channel, but a complete strategy for success, where you get toppers strategies, PYQ–GTQ discussions, current affairs updates, and important job-related information, all delivered by the country’s best teachers and industry experts.
If you also want to stay one step ahead in the race to success, subscribe to MADE EASY on YouTube and stay connected with us on social media.
MADE EASY — where preparation happens with confidence.
MADE EASY is a well-organized institute, complete in all aspects, and provides quality guidance for both written and personality tests. MADE EASY has produced top-ranked students in ESE, GATE, and various public sector exams. The publishing team regularly writes exam-related blogs based on conversations with the faculty, helping students prepare effectively for their exams.
