Data Brief

For further information contact your local STMicroelectronics sales office.

November 2006

Rev 1

1/4

4

EVAL6924D

EVAL6924D Battery charger system

with integrated Power Switch for Li-ION/Li-POLYMER

General description

The L6924D is a fully monolithic battery charger

dedicated to single-cell Li-Ion/Polymer battery

packs. It is the ideal solution for space-limited

applications, like PDAs, handheld equipment,

cellular phones, and digital cameras. It is

designed with BCD6 technology and integrates all

of the power elements (the Power MOSFET,

reverse blocking diode and the sense resistor) in

a small VFQFPN16 3mm x 3mm package.

When an external voltage regulated wall adapter

is used, the L6924D works in Linear Mode, and

charges the battery in a Constant

Current/Constant Voltage (CC/CV) profile.

Moreover, when a current-limited adapter is used,

the device can operate in Quasi-Pulse Mode,

dramatically reducing the power dissipation.

Regardless of the charging approach, a closed

loop thermal control avoids device overheating.

The device has an operating input voltage ranging

from 2.5V to 12V and it allows the user to program

many parameters, such as pre-charge current,

fast-charge current, pre-charge voltage threshold,

end-of-charge current threshold, and charge

timer.

The L6924D offers two open collector outputs for

diagnostic purposes, which can be used to either

drive two external LEDs or communicate with a

host microcontroller. Finally, the L6924D also

provides very flexible control of the charge

process termination and Gas Gauge capability, as

well as other functions, such as checking for

battery presence, and monitoring and protecting

the battery from unsafe thermal conditions.

The EVAL6924D Evaluation Board integrates the

linear battery charger as well as the external

components required for a typical application.

The input voltage range can be adjusted between

2.5V and 12V, while the output voltage is selected

by J4, between 4.1V and 4.2V, depending on the

battery type. The fast charge current is set to 500

mA through the 24K R5 resistor.

www.st.com

Evaluation board