Differences between Synchronous and Asynchronous Counter
There are two types of counters in digital logic circuit that are used to count the numbers of bits and these types depends upon the clock pulse applied to the flip flops.
1. Asynchronous Counter:
These are the counters in which we do not use universal clock, main clock is only applied to the first flip flop and then for rest of flip flops the output of previous flip flop is taken as a clock.
2. Synchronous Counter:
These are the counters in which we use a universal clock that is common to all flip flops. The Circuit diagram of Synchronous Counter is given Below:
Let’s see the difference between these two counters:
|S.NO||Synchronous Counter||Asynchronous Counter|
|1.||In synchronous counter we use a universal clock that is common to all flip flops through out the circuit. ||In asynchronous counter main clock is only applied to the first flip flop and then for rest of flip flops the output of previous flip flop is taken as a clock.|
|2.||Synchronous Counter is faster in operation as compared to Asynchronous Counter.||Asynchronous Counter is slower as compared to synchronous counter in operation.|
|3.||Synchronous Counter does not produce any decoding errors.||Asynchronous Counter produces decoding error.|
|4.||Synchronous Counter is also called Parallel Counter.||Asynchronous Counter is also called Serial Counter.|
|5.||Synchronous Counter designing as well implementation are complex due to increasing the number of states.||Asynchronous Counter designing as well as implementation is very easy.|
|6.||Synchronous Counter will operate in any desired count sequence.||Asynchronous Counter will operate only in fixed count sequence (UP/DOWN).|
|7.||Synchronous Counter examples are: Ring counter, Johnson counter.||Asynchronous Counter examples are: Ripple UP counter, Ripple DOWN counter.|
|8.||In synchronous counter, propagation delay is less.||In asynchronous counter, there is high propagation delay.|