ISL88731 SMBus Level 2 Battery Charger

The ISL88731 is a highly integrated Lithium-ion battery charger controller that can be programmed via the SMBus system management bus. It is designed for use in a smart battery charger (SBC) within a smart battery system (SBS) that regulates the charge power by automatically limiting the current from the AC adapter. High efficiency is achieved through a DC/DC synchronous-rectifier buck converter, which features diode emulation for improved light load efficiency and prevention of system bus boosting. The ISL88731 can charge one to four Lithium-ion series cells and can deliver up to 8A of charge current. It includes integrated MOSFET drivers and a bootstrap diode, resulting in fewer components and a reduced implementation area. Low offset current-sense amplifiers ensure high accuracy with 10m sense resistors, providing 0.5% end-of-charge battery voltage accuracy. Additionally, the ISL88731 features a digital output that signals the presence of the AC adapter and an analog output that indicates the adapter current with 4% accuracy. The device is offered in a compact 5mm x 5mm 28-lead Thin (0.8mm) QFN package and is available in Pb-Free options. An evaluation kit is also provided to expedite the design process.

The ISL88731 serves as a sophisticated solution for managing Lithium-ion battery charging in various applications. Its programmability via the SMBus allows for flexible integration into existing systems, enabling real-time monitoring and control of battery charging parameters. The device's capability to handle multiple series cells makes it suitable for a wide range of battery configurations, enhancing its versatility in different electronic devices.

The efficiency of the ISL88731 is particularly noteworthy, as the synchronous-rectifier buck converter minimizes power loss during operation. This design choice not only improves overall energy efficiency but also contributes to thermal management, allowing the device to operate within safe temperature limits even under heavy load conditions.

Integrated MOSFET drivers simplify the design process by reducing the number of external components required, which can lead to smaller PCB footprints and lower manufacturing costs. The inclusion of low offset current-sense amplifiers further enhances the accuracy of the charging process, ensuring that the battery is charged optimally without risking over-voltage conditions.

The digital and analog outputs provide valuable feedback for system diagnostics and monitoring. The digital output can be interfaced with microcontrollers or other logic devices to signal the operational status of the AC adapter, while the analog output allows for real-time current monitoring, which is critical for applications requiring precise power management.

The compact QFN package facilitates easy integration into space-constrained designs, making it ideal for portable electronics where size and weight are critical factors. The availability of a dedicated evaluation kit further supports developers in rapidly prototyping and testing their designs, ensuring that the ISL88731 can be effectively utilized in a variety of applications ranging from consumer electronics to industrial systems.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 effi ciency 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 10m 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. 🔗 External reference