A new type of direct-coupled FET logic (DCFL) flip-flop called the memory cell type flip-flop (MCFF) is presented. The MCFF operates faster than conventional DCFL flip-flops as well as enhances the advantages of DCFL such as low power consumption or high packing density. A D-flip-flop IC and a 1/8 divider IC were developed using the MCFF. These IC’s were fabricated using 0.2-μm-gate pseudomorphic inverted HEMT’s. The D-flip-flop IC is confirmed to operate up to 20 Gb/s by an originally developed measurement system. The 1/8 divider is toggled up to a maximum frequency of 25 GHz. These results prove that the MCFF enables DCFL circuits applicable not only for LSI but for SSI or MSI operating up to 20 Gb/s.