ZHCSFQ2C November 2016 – June 2018 TUSB422
PRODUCTION DATA.
Low battery power could cause conditions in which communication over USB Type-C can no longer be maintained. When this situation occurs, it is critical to transition to attached.SNK state so that power from VBUS can be used to charge the battery back to an operational level. This condition is known as Dead Battery Mode. The TUSB422 supports dead-battery mode by presenting Rd to both CC pins when VDD is no longer active.
In the dead-battery mode access to TUSB422 registers is not available. Upon exiting dead-battery mode, the TUSB422 enters mode dictated by the value of Role Control register.
NOTE
When exiting dead battery mode, the TUSB422's Rd is momentarily removed for about 100 µs during power up. This should not cause an issue in system since USB-C standard requires 100 ms debounce on CC pins.