High Input Voltage Charger The ISL9222 is a cost-effective, fully integrated high input voltage single-cell Li-ion battery charger. The charger uses a CC/CV charge profile required by Li-ion batteries. The charger accepts an input voltage up to 28V but is disabled when the input voltage exceeds the OVP threshold, typically 6.8V, to prevent excessive power dissipation. The 28V rating eliminates the overvoltage protection circuit required in a low input voltage charger. The charge current is user programmable with an external resistor. When the battery voltage is lower than typically 2.55V, the charger preconditions the battery with typically 20% of the programmed charge current. An internal thermal foldback function protects the charger from any thermal failure. AN indication pin PPR allows simple interface to a microprocessor or LED. When no adapter is attached or when disabled, the charger draws less than 1μA leakage current from the battery.