Difference Between Synchronous and Asynchronous Counter

As we know that in digital electronics, the counter is a sequential logic circuit consisting of a series of flip flops which is used to count the number of occurrences of input in terms of positive or negative edge transitions. Now based on the way the flip flops are triggered we can differentiate between synchronous and asynchronous counter.

What is the synchronous counter?

The synchronous counter also referred to as a parallel counter contains flip flops that are all in sync with each other. Their clock input is connected together and is triggered by the same external clock signal.

What is the Asynchronous counter?

 An asynchronous counter is the one also referred to as serial counter as here the flip flops that constitute the counter are connected serially and the input clock pulse is provided to the first flip flop in the connection.

Difference between synchronous and asynchronous counter:

  •  Synchronous counter all flip flops are triggered with the same clock simultaneously,  Asynchronous counter, different flip flops are triggered with different clock, not simultaneously.
  • The synchronous counter is faster than the Asynchronous counter in operation, the asynchronous counter is slower than the Synchronous counter in operation.
  • Synchronous counter designing and implementation are complex due to increasing the total number of states,  asynchronous counter designing as well as implementation is very easy.
  • The synchronous counter does not produce any decoding errors, the asynchronous counter produces decoding error.
  • The synchronous counter is also called a parallel counter, the asynchronous counter is also a serial counter.
  • The synchronous counter will operate in any desired count sequence, the asynchronous counter will operate only in a fixed count sequence
  • Synchronous counterexamples are ring counter, johnson counter, asynchronous counter-example counter, there is high propagation delay.