ZHCSGV1C June 2017 – March 2018 TPS25740B
PRODUCTION DATA.
The USB Type-C specification requires that the capacitance on the VBUS pin of an empty receptacle be below 10 µF. This is to protect legacy USB sources that are not designed to handle the larger inrush capacitance and which may be connected via an A-to-C cable. For applications with USB Type-C receptacles and large bulk capacitance, this means back-to-back blocking FETs are required as shown in Figure 21. However, for applications with a USB Type-C plug (that is, a captive cable) this requirement does not apply since an adaptor cable with a USB Type-C receptacle and a Type-A plug is not defined or allowed by the USB I/F. Figure 22 is a schematic for such applications.