ZHCSTD7A December 2021 – November 2023 BQ79631-Q1
PRODUCTION DATA
If the device is used as a base device, the UART interface requires the TX and RX pins are pulled up through a 10-kΩ to 100-kΩ resistor. Do not leave the TX and RX pins unconnected. The TX pin must be pulled high to prevent triggering an invalid communications frame during the idle state. When using a serial cable to connect to the host controller, connect the TX pullup on the host side and the RX pullup to the CVDD on the device side.
If the device is used as a stack device, the TX pin is disabled by default and is left floating. The RX pin is shorted to CVDD.
The NFAULT pin for a base device, if not used, must be left floating. Otherwise, pull it up with 100-kΩ to CVDD. The NFAULT pin on a stack device is floating.