Question

In a down counter, which flip-flop doesn’t toggle when the inverted output of the preceeding flip-flop goes from HIGH to LOW.

(a) MSB flip-flop

(b) LSB flip-flop

(c) Master slave flip-flop

(d) Latch

The question was posed to me in a national level competition.

My question is taken from Asynchronous Down Counter topic in chapter Counters of Digital Circuits

Answer 1

Right answer is (b) LSB flip-flop

For explanation: Since the LSB flip-flop changes its state at each negative transition of clock. That is why LSB flip-flop doesn’t have toggle.