Draw the circuit diagram of Asynchronous decade counter and explain its working.

Ans:

To  design  a  circuit diagram of decade  asynchronous  counter  initially  we  draw  the  circuit  for  MOD  16 asynchronous counter that counts from 0 to 15 by using four flip-flop (JK or T flipflop). This must count from 0 to 9 and then come to 0. The initial state to be skipped is 1010 (10) here Q₃ and Q₁ are 1 and Q₂ and Q₀ are 0 if we obtain Q₃ and Q₁ and applied these to a NAND gate after that the output of the NAND gate will be low only where Q₃ and Q₁ are high. Such signal can be utilized to asynchronously clear all flipflops to make the counting state 0000. In this method MOD 16 counter will be limited to count 10 states i.e. from 0 to 9.

The circuit diagram of Asynchronous decade counter