How many flip-flops are there in Decade Counter circuit?

How many flip-flops are there in Decade Counter circuit? Correct Answer 4

Concept:

For an ‘n’ flip flop counter,

• The total number of states = 2n (0 to 2n – 1)
• The largest number that can be stored in the counter = 2n – 1

To construct any MOD counter, the minimum number flip flops required such that:

Modulus ≤ 2n

Where n is the number of flip-flops and is the minimum value satisfying the above condition.

Calculation:

Number no. of flip – flops are required to construct a mod-10 counter (decade counter) is obtained as:

2n ≥ 10 i.e. n = 4

Note: A MOD-N counter is also called as a divide by N counter as the input frequency is divided by the number of states of the counter.