An AOT-control buck converter with Single Cycle Output Voltage Prediction (SCOVP) technique was proposed. Quasi-constant frequency operation with the input/output voltage and load variation was achieved. Furthermore, the switching frequency was set by off-chip resistor with improved accuracy. The switching frequency variation of the traditional AOT-controlled buck converter was analyzed, and an One-Shot Timer(OST) circuit with SCOVP technique was adopted. By predicting the output voltage through single duty cycle and load current, the operational frequency was stabilized. The converter was designed with in a 0.18 μm BCD process. Simulation results showed that only 13 kHz variation was realized with load current from 1 A to 5 A when the switching frequency was set as 2 MHz. Meanwhile, the switching frequency accuracy was enhanced from 88% to 99.35% with proposed SCOVP technique.