A droop compensation system includes a controlled current source that provides a scaled model of the PRM output current or VTM input current on an interface connection. A controlled resistance modeling the VTM effective series input resistance is connected across the interface terminal. The voltage developed across the controlled resistance by the controlled current establishes a correction signal representative of the VTM droop that is used to adjust the PRM output thereby compensating for the droop. A VTM control interface provides a mechanism for enabling and disabling the VTM. The VTM control circuitry may be powered by the interface connection, allowing the VTM to operate and process power when the VTM input voltage is below its normal minimum operating voltage, increasing the VTM dynamic range and allowing "soft start" into a capacitive load.