The power consumption of the MAX32630 increases 1-3mA when VDDB is powered and USB is not present. The MAX32630 microcontroller requires 3.3V at VDDB. This voltage should only be provided when USB D+/D- are connected to a USB host. Otherwise the MCU will consume additional power if 3.3V is provided while the USB connection is not connected. This is not listed in the Maxim datasheet and could potentially affect other products with USB as well. When not using a Maxim PMIC the easiest way to do this is by utilizing an LDO from USB 5V to VDDB which is enabled by the 5V provided from the USB host.