ZHCSFQ2C November 2016 – June 2018 TUSB422
PRODUCTION DATA.
A legacy Type-A charger will always have VBUS active. When customer plugs a Type-A to Type-C cable into both charger and TUSB422, the TUSB422 immediately detects Rp and then detects VBUS. If for some reason, there is a short between VBUS and CC, the TUSB422 the CC pin is exposed to VBUS voltage. The TUSB422 implements a detection of VBUS to CC short by monitoring voltage level on each the CC pin. If the initial voltage is above 3.5 V and TUSB422 is presenting Rd, then the TUSB422 will set the CC_FAULT status flag. The TUSB422 keeps the CC1_STATE and CC2_STATE flags in the open state. This indicates a invalid connection exist and user should be notified. The TUSB422 continues to look for a valid connection. Once user removes the fault condition (for example, selects a new cable), the TUSB422 indicates a valid connection by updating CC1_STATE and CC2_STATE to appropriate value.