Described herein are systems, architectures, circuits, devices, and methods for a DC-DC converter that dynamically adjusts a supply voltage to a power amplifier based on the number of resource blocks in a signal to be transmitted. The disclosed technologies estimate the number of resource blocks in a signal, generate a signal corresponding to the estimated number of resource blocks, and modify a supply voltage based on the generated signal. The disclosed DC-DC converters can be integrated into systems that employ power management strategies such as average power tracking (“APT”). In addition, the disclosed technologies can be used to improve existing APT-based systems.