The BQ77216 family of products provides a range of voltage and temperature monitoring including overvoltage (OVP), undervoltage (UVP), open wire (OW), and overtemperature (OT) protection for li-ion battery pack systems. Each cell is monitored independently for overvoltage, undervoltage, and open-wire conditions. With the addition of an external NTC thermistor, the device can detect overtemperature conditions.
In the BQ77216 device, an internal delay timer is initiated upon detection of an overvoltage, undervoltage, open-wire, or overtemperature condition. Upon expiration of the delay timer, the respective output is triggered into its active state (either high or low, depending on the configuration).
The overvoltage triggers the COUT pin if a fault is detected, and undervoltage triggers the DOUT pin if a fault is detected. If an overtemperature or open-wire fault is detected, then both the DOUT and COUT will be triggered. For quicker production-line testing, the BQ77216 device provides a Customer Test Mode (CTM) with greatly reduced delay time.