1 Features
1• 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 Iq
– < 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.