1 Features

• USB-Friendly 4.7-V to 28-V Input Operating Range
• Stand-Alone Charge Controller to Support 1 to 6 Li-Ion or Li-Polymer Battery Cells
• Up to 10-A Charge Current and Adapter Current
• 600-kHz NMOS-NMOS Synchronous Buck Converter
• High-Accuracy Voltage and Current Regulation
  • ±0.5% Charge Voltage Accuracy
  • ±3% Charge Current Accuracy
  • ±3% Adapter Current Accuracy
• Integration
  • Automatic System Power Selection From Adapter or Battery
  • Internal Loop Compensation
  • Internal Soft Start
  • Dynamic Power Management
• Safety Protection
  • Input Overvoltage Protection
  • Battery Thermistor Sense Hot/Cold Charge Suspend
  • Battery Detection
  • Reverse-Protection Input FET
  • Programmable Safety Timer
  • Charge Overcurrent Protection
  • Battery Short Protection
  • Battery Overvoltage Protection
  • Thermal Shutdown
• Status Outputs
  • Adapter Present
  • Charger Operation Status
• Charge Enable Pin
• 6-V Gate Drive for Synchronous Buck Converter
• 30-ns Driver Dead-Time and 99.5% Maximum Effective Duty Cycle
• Energy Star Low Quiescent Current I_q
  • < 15-µA Off-State Battery Discharge Current
  • < 1.5-mA Off-State Input Quiescent Current

2 Applications

• Tablet PCs
• Smart Phones
• Portable Media Players, Navigation Devices, Notebooks and Ultra-Mobile PCs
• Personal Digital Assistants
• Handheld Terminals
• Industrial and Medical Equipment

3 Description

The bq24618 device is highly integrated Li-ion or Li-polymer switched-mode battery-charge controller. The bq24618 offers a constant-frequency synchronous switching PWM controller with high-accuracy charge current and voltage regulation, charge preconditioning, termination, adapter current regulation and charge status monitoring.

The bq24618 operates from either a USB port or AC adapter and supports charge currents up to 10 A. The device charges the battery in three phases: preconditioning, constant current, and constant voltage. Charge is terminated when the current reaches a minimum user-selectable level. A programmable charge timer provides a safety backup for charge termination. The bq24618 automatically restarts the charge cycle if the battery voltage falls below an internal threshold, and enters a low-quiescent current sleep mode when the input voltage falls below the battery voltage.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

4 Revision History

Changes from A Revision (October 2011) to B Revision

• Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. Go

Changes from * Revision (October 2010) to A Revision

• Changed descriptions for PH and BTST pinsGo
• Corrected Equation 8Go