Datasheet

SLUU158 – April 2003
4
bq24020/bq24023 Charger (bqTINY-II) Evaluation Module
bq24020/bq24023 Charger (bqTINY-II) Evaluation Module
Portable Powe
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Contents
1 Introduction 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Test Summary 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Schematic 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Physical Layouts 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 List of Materials 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 References 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Introduction
This user’s guide describes the bq24020/bq24023 (bqTINY-II) evaluation module. The EVM
provides a convenient method for evaluating the performance of a charge management solution
for portable applications using the bq24020/bq24023 product family. A complete designed and
tested charger is presented. The charger is designed to deliver up to 1.0 A of continuous charge
current for single–cell Li-Ion or Li-Pol applications using a DC power supply. The charger is
programmed from the factory to deliver 0.7 A of charging current.
1.1 Background
The bqTINY-II series are highly integrated and flexible Li-Ion linear charge and system power
management devices targeted at space limited charger applications. The bqTINY-II series
offer integrated USB-port and ac-adapter supply management with autonomous power-source
selection, power FET and current sensor, high-accuracy current and voltage regulation, charge
status, and charge termination, in a single monolithic device. The bqTINY-II automatically
selects the USB-Port or the ac-adapter as the power source for the system. In the USB
configuration, the host can select from the two preset charge rates of 100 mA and 500 mA. In
the ac-adapter configuration an external resistor sets the magnitude of the system or charge
current. The bqTINY-II charges the battery in three phases: conditioning, constant current,
and constant voltage. Charge is terminated based on minimum current. An internal charge timer
provides a backup safety for charge termination. The bqTINY-II automatically restarts the
charge if the battery voltage falls below an internal threshold. The bqTINY-II automatically
enters sleep mode when both supplies are removed.