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LTC4058-4.2/LTC4058X-4.2

sn405842 405842fs

Standalone Linear

Li-Ion Battery Charger with

Thermal Regulation in DFN

s

Programmable Charge Current Up to 950mA

s

Complete Linear Charger in DFN Package

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No MOSFET, Sense Resistor or Blocking Diode

Required

s

Thermal Regulation Maximizes Charge Rate

Without Risk of Overheating*

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Battery Kelvin Sensing Improves Charging Accuracy

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Charges Directly from a USB Port

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C/10 Charge Termination

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Preset 4.2V Charge Voltage with

±1% Accuracy

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Charge Current Monitor Output for Gas Gauging*

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Automatic Recharge

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Charge Status Output

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“AC Present” Output

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2.9V Trickle Charge Threshold (LTC4058)

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Available Without Trickle Charge (LTC4058X)

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Soft-Start Limits Inrush Current

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Low Profile (3mm

× 3mm × 0.75mm) DFN Package

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Cellular Telephones, PDAs, MP3 Players

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Bluetooth Applications

, LTC and LT are registered trademarks of Linear Technology Corporation.

The LTC

voltage linear charger for single cell lithium-ion batteries.

Its DFN package and low external component count make

the LTC4058 ideally suited for portable applications. Fur-

thermore, the LTC4058 is designed to work within USB

power specifications.

The LTC4058 can Kelvin sense the battery terminal for

more accurate float voltage charging. No external sense

resistor or external blocking diode are required due to the

internal MOSFET architecture. Thermal feedback regu-

lates the charge current to limit the die temperature during

high power operation or high ambient temperature condi-

tions. The charge voltage is fixed at 4.2V and the charge

current is programmed with a resistor. The LTC4058

terminates the charge cycle when the charge current

drops to 10% of the programmed value after the final float

voltage is reached.

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

removed, the LTC4058 enters a low current state dropping

the battery drain current to less than 2

µA. Other features

include charge current monitor, undervoltage lockout,

automatic recharge and status pins to indicate charge

termination and the presence of an input voltage.

BAT

BSENSE

CHRG

1.65k

405842 TA01

1

µF

4.5V TO 6.5V

1-CELL

Li-Ion

BATTERY

LTC4058-4.2

600mA

ACPR

EN

PROG

GND

+

TIME (HOURS)

0

1.5

405842 TA02

0.5

1.0

2.25

700

600

500

400

300

200

100

0

4.75

4.50

4.25

4.00

3.75

3.50

3.25

3.00

0.25

0.75

1.25

2.0

1.75

CONSTANT

VOLTAGE

CONSTANT

CURRENT

Complete Charge Cycle (750mAh Battery)

*US Patent 6,522,118

Single Cell Li-Ion Battery Charger with Kelvin Sense

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO