A 0.8-V CMOS coupling current-mode injection-locked frequency divider (CCMILFD) with 19.5% locking range and a current-injection current-mode logic (CICML) frequency divider have been designed and fabricated using 0.13-mum 1p8m CMOS technology. In the proposed CCMILFD, the current-mode technique to minimize the loss of input signals and the coupling circuit to enlarge the phase response have been designed to increase the locking range. The locking range of the fabricated CCMILFD is 4.1 GHz with a power consumption of 1.51 mW from a power supply of 0.8 V. In the proposed CICML frequency divider, the current-injection interface is applied to the current inputs to make the circuit operated at a higher frequency with low power consumption under a low voltage supply. The operation frequency of the fabricated CICML frequency divider can divide the frequency range from CCMILFD and consume 1.89 mW from a 0.8-V voltage supply. The chip core areas of the CCMILFD and CICML frequency divider without pads are 0.23 and 0.015 mm2, respectively. The proposed circuits can be operated in a low supply voltage with the advantages of a wider locking range, a higher operation frequency, and lower power consumption.