In this article, a 10-MHz switching power converter is introduced to satisfy stringent requirements on 5G mobile Internet-of-Things (IoTs) power delivery. To achieve nanosecond power flipping, the converter utilizes a double adaptive bound (DAB) hysteretic control to improve load transient performance. A synchronized dc resistance offset cancellation scheme is naturally embedded to enhance load regulation accuracy while retaining fixed frequency operation. The controller circuit can be easily reconfigured to achieve a power scalable operation, which facilitates the converter with adaptive system power delivery capability to achieve high efficiency over a wide power range. An integrated circuit prototype is fabricated using a 180-nm CMOS process with an active die area of 0.175 mm 2 , achieving a peak power density of 14.3 W/mm 2 . In response to 1 A/3 ns load increase/decrease between zero and maximum power, it achieves 1% settling time of 247 ns/387 ns with 31 mV/60 mV voltage droop, respectively. With a nominal switching frequency of 10 MHz, the switching frequency variations are controlled below 0.1% despite of the use of a hysteretic control. And the output regulation accuracy is improved with only 0.3% error. Thanks to the proposed power scalable reconfiguration and adaptive power delivery, the converter achieves above 80% efficiency over 99.9% of 2.5-W full power range with a peak efficiency of 91%.