The MAX15026 synchronous step-down controller oper- ates from a 4.5V to 28V input voltage range and gener- ates an adjustable output voltage from 85% of the input voltage down to 0.6V while supporting loads up to 25A. The device allows monotonic startup into a prebiased bus without discharging the output and features adap- tive internal digital soft-start. The MAX15026 offers the ability to adjust the switching frequency from 200kHz to 2MHz with an external resis- tor. The MAX15026’s adaptive synchronous rectification eliminates the need for an external freewheeling Schottky diode. The device also utilizes the external low-side MOSFET’s on-resistance as a current-sense element, eliminating the need for a current-sense resis- tor. This protects the DC-DC components from damage during output overloaded conditions or output short- circuit faults without requiring a current-sense resistor. Hiccup-mode current limit reduces power dissipation during short-circuit conditions. The MAX15026 includes a power-good output and an enable input with precise turn-on/turn-off threshold, which can be used for input supply monitoring and for power sequencing. Additional protection features include sink-mode cur- rent limit and thermal shutdown. Sink-mode current limit prevents reverse inductor cur- rent from reaching dangerous levels when the device is sinking current from the output. The MAX15026 is available in a space-saving and ther- mally enhanced 3mm x 3mm, 14-pin TDFN-EP pack- age. The MAX15026 operates over the -40°C to +85°C temperature range.