ZHCSJR3B February 2019 – November 2019 BQ25887
PRODUCTION DATA.
The BQ2588x is a host controlled charger, but it can operate in default mode without host management. In default mode, the device can be used as an autonomous charger with no host or while host is in sleep mode. When the charger is in default mode, WD_STAT bit is HIGH. When the charger is in host mode, WD_STAT bit is LOW.
After power-on-reset, the device starts in default mode with watchdog timer expired, or default mode. All the registers are in the default settings. During default mode, any change on PSEL pin will make real time internal reference change.
In default mode, the device keeps charging the battery with default 12-hour fast charging safety timer.
A I2C write to the registers transitions the charger from default mode to host mode and watchdog timer is reset. All the device parameters can be programmed by the host. To keep the device in host mode, the host has to reset the watchdog timer by writing 1 to WD_RST bit before the watchdog timer expires (WD_STAT bit is set), or disable watchdog timer by setting WATCHDOG bits = 00.
When the watchdog timer (WD_STAT bit = 1) is expired, the device returns to default mode and all registers are reset to default values except as detailed in the Register Maps section. The Watchdog timer will be reset on any write if the watchdog timer has expired.