Ultra-low-power voltage protector for 3-series to 5-series cell Li-ion battery

The BQ77205 family of products provides a range of voltage and temperature monitoring, including overvoltage protection (OVP) and open-wire (OW) protection for Li-ion battery pack systems. Each cell is monitored independently for overvoltage and open-wire conditions.

In the BQ77205 device, an internal delay timer is initiated upon detection of an overvoltage or open-wire 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 OUT pin if a fault is detected. If an open-wire fault is detected, then the OUT is triggered. For quicker production-line testing, the BQ77205 device provides a Customer Test Mode (CTM) with significantly reduced delay time.