The AOZ22555QI is a high-efficiency, easy-to-use DC/DC synchronous buck regulator that operates up to 25V. The device is capable of supplying 15A of continuous output current with an output voltage adjustable down to 0.6V (±1.0%). The AOZ22555QI integrates an internal linear regulator to generate 5.3V VCC from input. If input voltage is lower than 5.3V, the linear regulator operates at low drop output mode, which allows the VCC voltage is equal to input voltage minus the drop-output voltage of the internal linear regulator. A proprietary constant on-time PWM control with input feed-forward results in ultra-fast transient response while maintaining relatively constant switching frequency over the entire input voltage range. A low 80ns minimum on-time enables very low output voltages at ultra-high operating frequencies. Integrated AC ripple injection enables all-ceramic low ESR output filter capacitors and smaller PCB footprint with no external components needed. Selectable PFM mode optimizes light load efficiency while forced PWM mode maintains constant frequency for lower harmonic noise. The device features multiple protection functions such as VCC under-voltage lockout, cycle-by-cycle current limit, output over-voltage protection, short-circuit protection, and thermal shutdown. The AOZ22555QI is available in a 4mm×4mm QFN-23L package and is rated over a -40°C to +85°C ambient temperature range.