An ultra−low power protection integrated circuit managing lithium−ion batteries from 3 to 5 cells in series with accurate batter

Each cell in the battery pack is monitored for an over−voltage and under−voltage condition. Upon detecting an over−voltage, the ODI pin will assert indicating a fault condition and stay asserted until the fault is cleared. During an under voltage condition, the UDI pin will also assert indicating the fault but will have a pulse width that is pre−set in the protector. Both over and under voltage detections have a hard coded pre−set delay time before fault indication. Pulling the ENB high will start a measurement of the battery pack voltage which will be compared to a pre−set detection threshold table. If a threshold voltage is exceeded the protector will power the corresponding LED to indicate state of charge of the pack. Hardware protection and battery monitoring run autonomously and allows operation without a microcontroller.