ISL9221

Description

The ISL9221 Lithium Ion charging IC is designed to meet the charging requirements of most of todays handheld devices. The IC provides two inputs for either USB connection where the current is limited by the USB standard or for powering/charging from a power adapter. If the voltage at either VUSB or VDC pin is within the safe allowable range, the PPR pin is pulled low indicating to the system processor that external power is available. Charging can be enabled/disabled by controlling the state of the EN pin. While charging, the CHG pin is pulled low indicating the battery is being charged. The battery is charged to 4.2V with only a 1% error across the temperature range. USB charge current, Adapter charge current and charge termination currents can be programmed via external resistors. The ISL9221 adds an additional feature in providing a limited amount of current to system architecture while protecting the system from destructively high voltage. The device contains Thermal regulation and protection to provide additional safety features of this device. When the temperature exceeds +125C, the current will fold back to reduce and control the die temperature.