High Input Voltage Charger With Power Path Management

The ISL9301 is a fully integrated high input voltage single-cell Li-ion battery charger with power path management function. This charger performs the CC/CV charge function required by Li-ion batteries. The charger accepts an input voltage up to 28V but is disabled when the input voltage exceeds 10.5V OVP threshold. The 28V rating eliminates the overvoltage protection circuit required in a low-voltage charger. The charge current and the end-of-charge (EOC) current are programmable with external resistors. When the battery voltage is lower than 2. 8V, the charger preconditions the battery with 16% of the programmed charge current. When the charge current reduces to the programmable EOC current level during the CV charge phase, the EOC indicator (CHG) will toggle to logic HIGH to indicate the end-of-charge condition.

The charger will continue to charge until the user-programmed timeout interval has elapsed, then the charger is terminated. The ISL9301 uses separate power paths to supply the system load and charge the battery. This feature allows the system to immediately operate with a completely discharged battery. This feature also allows the charge to terminate when the battery is full while continuing to supply the system with the input source, thus minimizing unnecessary charge/discharge cycles and improving the battery life. Two indication pins (PPR and CHG) allow simple interface to a microprocessor or LEDs.