This paper presents adiabatic flip-flops operating on near-threshold supply voltages. The near-threshold adiabatic flip-flops and sequential circuits are realized with improved CAL (Clocked Adiabatic Logic) circuits using a single-phase power clock. An auxiliary clock generator is used to obtain the non-overlap sinusoidal auxiliary signal pair. A near-threshold mode-10 counter is implemented. All circuits are simulated using Predictive Technology Model (PTM) 45nm process. The near-threshold adiabatic circuits attain large energy savings over a wide range of frequencies, as compared with conventional static CMOS logic circuits.