The ISL88731 is a highly integrated Lithium-ion battery charger controller, programmable over the SMBus system management bus (SMBus). The ISL88731 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 and system bus boosting prevention. The ISL88731 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 area. Low offset current-sense amplifiers provide high accuracy with 10mΩ sense resistors. The ISL88731 provides 0.5% end-of-charge battery voltage accuracy.

The ISL88731 provides a digital output that indicates the presence of the AC adapter as well as an analog output which indicates the adapter current within 4% accuracy.

The ISL88731 is available in a small 5mmx5mm 28 Ld Thin (0.8mm) QFN package. An evaluation kit is available to reduce design time. The ISL88731 is available in Pb-Free packages

• 0.5% Battery Voltage Accuracy
• 3% Adapter Current Limit Accuracy
• 3% Charge Current Accuracy
• SMBus 2-Wire Serial Interface
• Battery Short Circuit Protection
• Fast Response for Pulse-Charging
• Fast System-Load Transient Response
• Monitor Outputs
  • Adapter Current (3% Accuracy)
  • AC-Adapter Detection
• 11-Bit Battery Voltage Setting
• 6 Bit Charge Current/Adapter Current Setting
• 8A Maximum Battery Charger Current
• 11A Maximum Adapter Current
• +8V to +28V Adapter Voltage Range
• Pb-Free (RoHS Compliant)

• Notebook Computers
• Tablet PCs
• Portable Equipment with Rechargeable Batteries