User's Manual

February 2017
DocID0xxxxx Rev 0.xx 14/27
This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change
without notice. ww w.st.com
NOTE: when using the SPSGPE in a USB self-powered application, USB back-voltage test requirement
must be met (i.e. a maximum of 400 mV may be measured on the VBUS, D+, or D- when the device is not
plugged into a USB port). For this purposes, SPSGPE requires to receive on the pin USB_DEV_CONN a
signal indicating, when set at high logical level, that the VBUS is detected in order to properly control the
internal pull-up resistor connected to D+ line available internally to the STM32L151RDY6. For further
details, please refer to STM32L151RDY6 datasheet.