D-type flip-flop unit and frequency divider with the same

The invention provides a D-type flip-flop unit, which comprises a first two-input NAND gate, a second two-input NAND gate, a first inverter, a second inverter, a third inverter and a first D-type flip-flop. The invention also provides a frequency divider with the D-type flip-flop unit, which can input a frequency dividing number through a group of N-bit binary digital signals M, and the input frequency is divided by M +1 to generate an output frequency. The frequency divider with the D-type flip-flop unit comprises N cascading D-type flip-flop units, a logic gate circuit, and an internal reset circuit. The D-type flip-flop unit can use fewer devices to realize more complex circuit, and reduces circuit complexity and flow use area. The multi-bit programmable and modular frequency divider can divide frequency for any one integer ranging from 1 to 2N, and can meet the requirements of high-speed RF circuit and simple structure.