As mentioned earlier, when the output of the sequential circuit depends only on the present state of the flip-flop, the sequential circuit is referred to as Moore Circuit. Let us see one example of Moore circuits. Fig. 3.37 shows a sequential circuit which consists of two JK flip-flops and AND gate. The circuit has one input X and one output Y.
As shown in the Fig. 3.38, input is used to determine the inputs of the flip-flops. It is not used to determine the output. The output is derived using only present states of the flip-flops or combination of it (in this case Y=QAQB).
In general form the Moore circuit can be represented with its block schematic as shown in Fig. 3.38 (a) and (b).
In the Moore circuit, as output depends only on present state of flip-flops, it appears only after the clock pulse is applied, i.e. it varies in synchronism with the clock input.