USB (Sheets 3, 4 and 5): Circuit to avoiding Back-driving Problems
See also Figure 32 in https://www.picmg.org/wp-content/uploads/PICMG_COMDG_2.0-RELEASED-2013-12-06.pdf
See also Figure 32 in https://www.picmg.org/wp-content/uploads/PICMG_COMDG_2.0-RELEASED-2013-12-06.pdf