LTC4059/LTC4059A

1

4059fb

■

Wireless PDAs

■

Wireless Headsets

■

Programmable Charge Current Up to 900mA

Termination

■

Constant-Current/Constant-Voltage Operation with

Thermal Regulation to Maximize Charging Rate

Without Risk of Overheating

■

Constant-Current Source Mode for Charging

Nickel Batteries (LTC4059 Only)

(LTC4059A Only)

Diode Required

■

Operating Supply Voltage from 3.75V to 8V

USB Port

■

Preset 4.2V Charge Voltage with 0.6% Accuracy

µA Supply Current in Shutdown Mode

× 2mm) DFN Package

900mA Linear Li-Ion

Battery Chargers with

Thermal Regulation in 2

× 2 DFN

The LTC

voltage linear chargers for single cell lithium-ion batteries.

Their 2mm

× 2mm DFN package and low external compo-

nent count make these chargers especially well suited for

portable applications. Furthermore, they are designed to

work within USB power specifications.

No external sense resistor, MOSFET or blocking diode is

required. Thermal feedback regulates the charge current

to limit the die temperature during high power operation or

high ambient thermal conditions. The charge voltage is

fixed at 4.2V and the charge current is programmable.

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

removed, the LTC4059/LTC4059A automatically enter a low

current state, dropping the battery current drain to less than

1

µA. With power applied, they can be put into shutdown

mode, reducing the supply current to 10

µA.

The LTC4059A features an open-drain status pin to indi-

cate the presence of an input voltage. The LTC4059 can be

used as a constant-current source to charge Nickel cells.

Other features include undervoltage lockout protection

and a current monitor pin which can indicate when to

terminate a charge cycle.

The LTC4059/LTC4059A are available in a 6-lead, low

profile (0.75mm) 2mm

× 2mm DFN package.

Complete Charge Cycle (800mAh Battery)

TIME (HOURS)

0

500

600

700

2

4059 TA02

400

300

0.5

1

1.5

2.5

200

100

0

4.0

4.2

4.4

3.8

3.6

3.4

3.2

3.0

CONSTANT

CURRENT

CONSTANT

VOLTAGE

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

LTC4059A

4.5V TO 8V

EN

GND

BAT

1

µF

2k

50k

4.2V

Li-Ion

BATTERY

600mA

µP

4059 TA01

ACPR

PROG

+

, 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.