LTC4002 View Datasheet(PDF) - Linear Technology

Part Name

Description

Manufacturer

LTC4002

Standalone Li-Ion Switch Mode Battery Charger

Linear Technology 

LTC4002

Standalone Li-Ion

Switch Mode Battery Charger

FEATURES

■ Wide Input Supply Range:

4.7V to 22V – 4.2 Version

8.9V to 22V – 8.4 Version

■ High Efficiency Current Mode PWM Controller with

500kHz Switching Frequency

■ ±1% Charge Voltage Accuracy

■ End-of-Charge Current Detection Output

■ 3 Hour Charge Termination Timer

■ Constant Switching Frequency for Minimum Noise

■ ±5% Charge Current Accuracy

■ Low 10µA Reverse Battery Drain Current

■ Automatic Battery Recharge

■ Automatic Shutdown When Input Supply is Removed

■ Automatic Trickle Charging of Low Voltage Batteries

■ Battery Temperature Sensing and Charge

Qualification

■ Stable with Ceramic Output Capacitor

■ 8-Lead SO and 10-Lead DFN Packages

U

APPLICATIO S

■ Portable Computers

■ Charging Docks

■ Handheld Instruments

DESCRIPTIO

The LTC®4002 is a complete battery charger controller for

one (4.2V) or two (8.4V) cell lithium-ion batteries. With a

500kHz switching frequency, the LTC4002 provides a

small, simple and efficient solution to fast charge Li-Ion

batteries from a wide range of supply voltages. An external

sense resistor sets the charge current with ±5% accuracy.

An internal resistor divider and precision reference set the

final float voltage to 4.2V per cell with ±1% accuracy.

When the input supply is removed, the LTC4002 automati-

cally enters a low current sleep mode, dropping the battery

drain current to 10µA. An internal comparator detects the

near end-of-charge condition while an internal timer sets

the total charge time and terminates the charge cycle. After

the charge cycle ends, if the battery voltage drops below

4.05V per cell, a new charge cycle will automatically begin.

The LTC4002 is available in the 8-lead SO and 10-lead DFN

packages.

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

All other trademarks are the property of their respective owners.

TYPICAL APPLICATIO

1.5A Single Cell Li-Ion Battery Charger

VIN

5V TO 22V

CHARGE

STATUS

BAT

2k

0.1µF

VCC

GATE

10µF

LTC4002ES8-4.2

CHRG SENSE

6.8µH

68mΩ

0.47µF

2.2k

COMP

NTC

T

BAT

GND

22µF

+ Li-Ion

BATTERY

10k

NTC

4002 TA01

NTC: DALE NTHS-1206N02

Efficiency vs Input Voltage

100

(CURVES INCLUDE

INPUT DIODE)

90

VBAT = 4V

80

VBAT = 3.8V

70

60

5

10

15

20

25

INPUT VOLTAGE (V)

4002 TA02

4002f

1

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