TI Introduces SMBus Battery Charge IC for Multi-Cell Packs
Texas Instruments Inc. (TI) has announced its first integrated battery charge controller with a System Management Bus (SMBus) interface aimed at multi-cell, multi-chemistry battery packs used in portable applications.
TI's highly accurate and power efficient bq24721 charge management device easily interfaces to a system's host controller through an SMBus communications interface. The charger offers 0.4 percent accuracy on charge voltage regulation and two percent accuracy on current amplifier outputs. Using a synchronous NMOS-NMOS rectifier, the easy-to-design device can achieve power efficiencies up to 94 percent.
The bq24721 integrates several high-performance features, including the system power selector function, which automatically selects the AC adaptor or the battery to properly manage the system load. The device's dynamic power management (DPM) function controls the charge current depending on system load conditions, avoiding AC adaptor overload. In addition, high accuracy current sense amplifiers enable accurate measurement of either the charge current or the AC adaptor current, allowing termination of the "non-smart" packs and monitoring of overall system power.
Key Features of the bq24721: High-Efficiency NMOS-NMOS Synchronous DC/DC Buck Converter with User-Selectable 300 kHz or 500 kHz Frequency. Programmable Battery Voltage, Charge Current and AC Adaptor Current via SMBus. Highly Accurate Charge Management: 0.4 Percent Charge Voltage Accuracy, 3 Percent Charge Current Regulation Accuracy and 3 Percent Adaptor Current Regulation Accuracy. Two Percent Accuracy Integrated Charge and AC Adaptor 20x Current Amplifier Output. Autonomous Power Source Selector and Dynamic Power Management. Battery Pack Voltage Range 0 V to 19.2 V for Three- to Four-cell Li-Ion Series Cells. AC Adaptor Operating Range 8 V to 28 V. Charger Soft Start, Charge Over-current Protection and IC Temperature Monitoring
The bq24721 is available now from TI and its authorized distributors. The battery charge management IC comes in a 32-pin, 5 mm x 5 mm QFN package, and suggested pricing is $4.90 in 1,000 piece quantities.
