SLVSD02E March 2015 – August 2021 TPS65982
Data Contact Detect follows the definition in the USB BC1.2 specification. The detection scheme sources a current IDP_SRC into the D+ pin of the USB connection. The current is sourced into either the C_USB_TP (top) or C_USB_BP (bottom) D+ pin based on the determined cable/device orientation. A resistance RDM_DWN is connected between the D– pin and GND. Again, this resistance is connected to either the C_USB_TN (top) or C_USB_BN (bottom) D– pin based on the determined cable/device orientation. The middle section of Figure 9-39, the current source IDP_SRC and the pulldown resistance RDM_DWN, is activated during data contact detection.