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.
Feature
- 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
- Automatic System Power Selection From
- 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 Iq
- < 15-μA Off-State Battery Discharge Current
- < 1.5-mA Off-State Input Quiescent Current
- APPLICATIONS
- Tablet PCs
- Smart Phones
- Portable Media Players, Navigation Devices,
Notebooks and Ultra-Mobile PCs - Personal Digital Assistants
- Handheld Terminals
- Industrial and Medical Equipment
