ZHCSMR2B December 2020 – December 2021 BQ76942
The BQ76942 device can be configured to operate in a completely standalone mode, without any host processor in the system, or together with a host processor. If in standalone mode, the device can monitor conditions, control FETs and an in-line fuse based on threshold settings, and recover FETs when conditions allow, all without requiring any interaction with an external processor. If a host processor is present, the device can still be configured to operate fully autonomously, while the host processor can read measurements and exercise control as desired. In addition, the device can be configured for manual host control, such that the device can monitor and provide a flag when a protection alert or fault has occurred, but will rely on the host to disable FETs.
The host processor can interface with the BQ76942 device through a serial bus as well as selected pin controls. Serial bus communication through I2C (supporting speeds up to 400 kHz), SPI or HDQ is available, with the serial bus configured for I2C by default in the BQ76942, while the default communications mode may differ for other versions of the device. The pin controls available include RST_SHUT, ALERT, CFETOFF, DFETOFF, DDSG, and DCHG, which are described in detail below.