Description
The ISL88732 is a highly integrated Lithium-ion battery charger controller, programmable over the SMBus system management bus (SMBus). The ISL88732 is intended to be used in a smart battery charger (SBC) within a smart battery system (SBS) that throttles the charge power such that the current from the AC adapter is automatically limited. High efficiency is achieved with a DC/DC synchronous-rectifier buck converter, equipped with diode emulation for enhanced light load efficiency. The ISL88732 charges one to four Lithium-ion series cells and delivers up to 8A charge current. Integrated MOSFET drivers and bootstrap diode result in fewer components and smaller implementation areas. Low offset current-sense amplifiers provide high accuracy with 10mΩ sense resistors. The ISL88732 provides 0. 5% end-of-charge battery voltage accuracy. The ISL88732 is available in a small 5mmx5mm 28 Ld Thin (0. 8mm) QFN package. Boost Mode If the system load current is higher than the adapter current limit, ISL88732 will operate in boost mode to draw power from the battery and boost it to adapter voltage. The system load current will be supplied partly from the adapter and partly from the battery. ISL88732 performs this function by (1) detecting high adapter current, (2) reducing charge current to zero, and (3) controlling LFET ON time to boost current from the battery and limit current from the adapter.
