1 Features

300-kHz NMOS-NMOS Synchronous Buck Converter
Stand-Alone Charger Designed Specifically for Lithium Phosphate
5-V to 28-V VCC Operating Range, Supports 1 to 7 Battery Cells
High-Accuracy Voltage and Current Regulation
- ±0.5% Charge Voltage Accuracy
- ±3% Charge Current Accuracy
Integration
- Internal Loop Compensation
- Internal Soft Start
Safety
- Input Overvoltage Protection
- Battery Thermistor Sense Suspend Charge at Hot/Cold Charge Suspend and Automatically I_CHARGE/8 at WARM/COOL
- Battery Detection
- Built-In 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 99.95% Maximum Effective Duty Cycle
16-Pin 3.5-mm × 3.5-mm QFN Package
Energy Star Low I_q
- < 15-μA Off-State Battery Discharge Current
- < 1.5-mA Off-State Input Quiescent Current

2 Applications

Power Tools and Portable Equipment
Personal Digital Assistants
Handheld Terminals
Industrial and Medical Equipment
Netbooks, Mobile Internet Devices, and Ultramobile PCs

3 Description

The bq24620 device is a highly integrated lithium phosphate switched-mode battery charge controller. The device offers a constant-frequency synchronous switching PWM controller with high-accuracy charge current and voltage regulation, charge preconditioning, termination, and charge status monitoring.

The bq24620 charges the battery in three phases: preconditioning, constant current, and constant voltage.

Device Information⁽¹⁾

PART NUMBER	PACKAGE	BODY SIZE (NOM)
bq24620	VQFN (16)	3.50 mm × 3.50 mm

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 sectionGo

Changes from * Revision (March 2010) to A Revision