AiT Semiconductor

A4054A Datasheet Preview

A4054A Datasheet

800mA STANDALONE LINEAR Li-ion BATTERY CHARGER

No Preview Available !

AiT Semiconductor Inc.

www.ait-ic.com

A4054A

800mA STANDALONE LINEAR Li-ion BATTERY CHARGER

THERMAL REGULATION

DESCRIPTION

The A4054A is a complete constant current / constant

voltage linear charger for single cell Lithium-Ion

batteries. No external sense resistor is needed, and

no blocking diode is required due to the internal

MOSFET architecture. Thermal feedback regulates

the charge current to limit the die temperature during

high power operation or high ambient temperature.

The charge voltage is fixed at 4.2V, and the charge

current can be programmed externally with a single

resistor. The A4054A automatically terminates the

charge cycle when the charge current drops to 1/10

the programmed value after the final float voltage is

reached.

When the input supply (wall adapter or USB supply) is

removed, the A4054A automatically enters a low

current state, dropping the battery drain current to

less than 2μA. The A4054A can be put into shutdown

mode, reducing the supply current to 25μA. Other

features include charge current monitor, under-voltage

lockout, automatic recharge and a status pin to

indicate charge termination and the presence of an

input voltage. A4054A will check the battery voltage

first, it will not start charging unless the battery

voltage is below the auto-rechrage threshold.

The A4054A is available in SOT-25 packages.

FEATURES

 Programmable Charge Current Up to 800mA

 No MOSFET, Sense Resistor or Blocking

Diode Required

 Preset 4.2V Charge Voltage with ±1%

Accuracy

 Charge Current Monitor Output for Gas

Gauging

 Thermal Regulation Maximizes Charge Rate

Without Risk of Overheating

 Charges Single Cell Li-Ion Batteries Directly

from USB Port

 Over-Voltage Protect

 Automatic Recharge

 Charge Status Output Pin

 C/10 Charge Termination

 25μA Supply Current in Shutdown

 2.9V Trickle Charge Threshold

 Soft-Start Limits Inrush Current

 Available in SOT-25 Packages

APPLICATION

 Cellular and Smart Phones

 Charging Docks and Cradles

 Blue Tooth Applications

 PDAs

 MP3/MP4/MP5 Players

ORDERING INFORMATION

TYPICAL APPLICATION

Package Type

Part Number

SOT-25

A4054AE5R

A4054AE5VR

Note

R: Tape & Reel

V: Halogen free Package

AiT provides all RoHS products

Suffix “V” means Halogen free Package

REV1.1

- DEC 2008 RELEASE, JUN 2012 UPDATED -

-1-

AiT Semiconductor

A4054A Datasheet Preview

A4054A Datasheet

800mA STANDALONE LINEAR Li-ion BATTERY CHARGER

No Preview Available !

AiT Semiconductor Inc.

www.ait-ic.com

A4054A

800mA STANDALONE LINEAR Li-ion BATTERY CHARGER

THERMAL REGULATION

PIN DESCRIPTION

Pin #

Symbol

CHRGb

GND

BAT

VCC

PROG

Top View

Function

Open-Drain Charge Status Output. When the battery is charging, the CHRGb pin is

pulled low by an internal N-channel MOSFET. When the charge cycle is completed, a

weak pull-down of approximately 12μA is connected to the CHRGb pin, indicating an

“AC present” condition. When the A4054A detects an under-voltage lockout condition,

CHRGb is forced high impedance.

Ground

Charge Current Output. Provides charge current to the battery and regulates the final

float voltage to 4.2V. An internal precision resistor divider from this pin sets the float

voltage which is disconnected in shutdown mode.

Positive Input Supply Voltage. Provides power to the charger. VCC can range from

4.25V to 6.5V and should be bypassed with at least a 1μF capacitor. When VCC drops

to within 30mV of the BAT pin voltage, the A4054A enters shutdown mode, dropping

IBAT to less than 2μA.

Charge Current Program, Charge Current Monitor and Shutdown Pin. The charge

current is Programmed by connecting a 1% resistor, RPROG, from this pin to ground.

When charging in constant-current mode, this pin servos to 1V. In all modes, the voltage on

this pin can be used to measure the charge current using the following formula:

IBAT = (VPROG / RPROG) • 1000

The PROG pin can also be used to shut down the charger. Disconnecting the Program

resistor from ground allows a 3μA current to pull the PROG pin high. When it reaches

the 1.21V shutdown threshold voltage, the charger enters shutdown mode, charging

stops and the input supply current drops to 25μA. This pin is also clamped to

approximately 2.4V. Driving this pin to voltages beyond the clamp voltage will draw

currents as high as 1.5mA. Reconnecting RPROG to ground will return the charger to

normal operation.

REV1.1

- DEC 2008 RELEASE, JUN 2012 UPDATED -

-2-

900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf

A4054A Datasheet Preview

A4054A Datasheet

800mA STANDALONE LINEAR Li-ion BATTERY CHARGER

A4054A Datasheet Preview

A4054A Datasheet

800mA STANDALONE LINEAR Li-ion BATTERY CHARGER

Similar Datasheet

Part Number Start With