1

LTC4065L/LTC4065LX

4065lxfa

■

Portable MP3 Players, Wireless Headsets

■

Bluetooth Applications

Standalone 250mA Li-Ion

Battery Charger in 2

× 2 DFN

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Charge Current Programmable up to 250mA with

5% Accuracy

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Complete Linear Charger in 2mm

××××× 2mm DFN

Package

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C/10 Charge Current Detection Output

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Timer Termination

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No External MOSFET, Sense Resistor or Blocking

Diode Required

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Preset 4.2V Float Voltage with 0.6% Accuracy

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Constant-Current/Constant-Voltage Operation with

Thermal Feedback to Maximize Charging Rate

Without Risk of Overheating

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Charge Current Monitor Output for Gas Gauging

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Automatic Recharge

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Charges Single Cell Li-Ion Batteries Directly from

USB Port

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20

µA Supply Current in Shutdown Mode

× 2mm) DFN Package

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

The LTC

voltage linear charger for single-cell lithium-ion batteries.

Its small size and ability to accurately regulate low charge

currents make the LTC4065L especially well-suited for

portable applications using low capacity rechargeable

lithium-ion cells. Furthermore, LTC4065L is specifically

designed to work within USB power specifications.

The CHRG pin indicates when charge current has dropped

to ten percent of its programmed value (C/10). An internal

timer terminates charging according to battery manufac-

turer specifications.

No external sense resistor or blocking diode is required

due to the internal MOSFET architecture. Thermal feed-

back regulates charge current to limit the die temperature

during high power operation or high ambient temperature

conditions.

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

removed, the LTC4065L automatically enters a low cur-

rent state, dropping battery drain current to less than 1

µA.

With power applied, LTC4065L can be put into shutdown

mode, reducing the supply current to less than 20

µA.

The full-featured LTC4065L also includes automatic re-

charge, low-battery charge conditioning (trickle charging)

and soft-start (to limit inrush current).

The LTC4065L is available in a tiny 6-lead, low profile

(0.75mm) 2mm

× 2mm DFN package.

Standalone Li-Ion Battery Charger

+

R1

510

Ω

100mA

R3

2k

4065L TA01

4.2V

Li-Ion

BATTERY

4.3V TO 5.5V

C1

1

µF

LTC4065L

CHRG

EN

BAT

PROG

GND

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Multifunction Wristwatches

Complete Charge Cycle (180mAh Battery)

TIME (HOURS)

0

30

90

100

110

1

2

2.5

4065 TA02

10

70

50

20

80

0

60

40

4.3

3.5

4.1

3.3

3.9

3.7

0.5

1.5

3

3.5

4

4.5

CONSTANT

CURRENT

CONSTANT

VOLTAGE

CHRG

TRANSITION

CHARGE

TERMINATION

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

All other trademarks are the property of their respective owners.

Protected by U.S. Patents including 6522118, 6700364.