The MAX8650 synchronous PWM buck controller operates from a 4.5V to 28V input and generates an adjustable 0.7V to 5.5V output voltage at loads up to 25A. The MAX8650 uses a peak current-mode control architecture with an adjustable (200kHz to 1.2MHz) constant switching frequency and is externally synchronizable. The IC's current limit uses the inductor's DC resistance to improve efficiency or an external sense resistor for high accuracy. The current-limit threshold is adjusted with an external resistor. Foldback-type current limit can be implemented to reduce the power dissipation in overload or short-circuit conditions. Short-circuit protection is provided based on sensing the current in the low-side MOSFET. A reference input is provided for use with a high-accuracy external reference or for double-data-rate (DDR)-tracking applications.