Patent ID: 7973574

Claim:
A frequency divider, which receives a first signal and generates a second signal by dividing a frequency of the first signal, comprising: a plurality of flip-flops that each performs an operation of latching and outputting an input signal based on the first signal; and at least one switch unit including a plurality of individual switches positioned between adjacent flip-flops that are separately switched in response to a control signal to modify a signal transfer path between the plurality of the flip-flops, wherein different numbers of flip-flops are activated in response to one of first and second statuses of the control signal so that the frequency of the first signal is divided by different multiples, wherein the plurality of the flip-flops comprise first through fourth flip-flops that are connected to one another, and the first through fourth flip-flops are electrically connected to one another in response to the first status of the control signal to divide the frequency of the first signal by four and output the frequency-divided first signal, and two of the first through fourth flip-flops are electrically connected to each other in response to the second status of the control signal to divide the frequency of the first signal by two and output the frequency-divided first signal, and wherein the at least one switch unit comprises: a first switch unit connecting an output of the first flip-flop with an input of the second flip-flop; a second switch unit connecting an output of the third flip-flop with an input of the fourth flip-flop; and a third switch unit connecting an output of the first flip-flop with an input of the fourth flip-flop.