SPRUI97E May 2017 – September 2025
Processor port USB2 is implemented as either USB host (master) or USB device (slave). It supports only the USB2.1 (high speed and lower) data rates. The connector on the board, J45, is a USB2.1 Micro-AB connector. The ESD device implemented on this USB port is the TPD4S012.
Since processor USB port 2 supports host mode, it has the capability to drive 5.0V power on the VBUS pin. The TPS2051 load switch is controlled by the USB2_DRVVBUS pin for this purpose.
The USB2.1 standard defines different ranges of capacitance for the VBUS pin depending on whether it is host or device. Since this port can do either, the AM571x IDK EVM provides the capability to meet either requirement. The VBUS pin from the connector contains a 4.7µF capacitor that is appropriate for device mode operation. When operating in host mode, 2-pin header J50 can be shorted to add 150µF of additional capacitance to the VBUS pin. The shunt for this header is shown on the schematic as M2. It is not installed on units when shipped as we expect this port to primarily be used in device mode.