A power converter for a load with varying power requirements dynamically adjusts its supply voltage to the load so as to track the radio frequency (RF) envelope of the signal being carried by the load. The supply voltage can be provided by a multiple-output charge pump providing multiple output voltage levels concurrently, and a switch to provide a selected one of the different output voltage levels as the supply voltage to the load. A controller controls the switch to dynamically modify the voltage level selected for output as the supply voltage such that the supply voltage tracks the RF envelope of the signal being carried by the load. As the switching losses of transistors of the power converter may exceed the power savings achieved through envelope tracking, the power converter employs a peak following frequency divider circuit that limits the switching frequency of the power converter to a threshold frequency.