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.