A flip flop includes a precharge circuit configured to charge a first node by bridging a power voltage node and the first node, the charging of the first node by the precharge circuit according to a voltage level of a clock signal, the charging of the first node by the precharge circuit based on at least two PMOS transistors arranged in series, a discharge circuit configured to discharge the first node by bridging the first node and a ground node, the discharging of the first node according to an input signal and the clock signal, and a second node configured to be charged or discharged, the charging and the discharging of the second node according to a voltage level of the first node.