USB PD EPR power supplies have a wide operating voltage range (5 V to 48 V) which is challenging for the designer looking to achieve high efficiency, regulation, power density and thermal performance. In this presentation, a USB PD EPR solution with output stacked configuration meeting the USB PD 3.1 specification is proposed. With the proposed solution, two flyback-based power supplies each 24 V/120 W are stacked on the secondary side to achieve 48 V/240 W power. Only one power supply feeds the load in SPR mode for better efficiency. The stacking and unstacking of power supplies are controlled using the microcontroller based on the sink’s PD contract. The key features of the stacked power supply include power density >27 W/in3, peak efficiency >95%, high efficiency even at SPR operation, simple control and ZVS operation. The special bus architecture of the proposed system provides smooth voltage transitions between SPR and EPR modes. The overall block diagram of the EPR solution and bus switch architecture are presented along with the hardware prototype and experimental validation. More results will be discussed in the final presentation.