1

LTC1729 Series

s

Trickle Charge Preconditioning If Cell < 2.7V

s

Charging Enabled When 0

°C < T < 50°C

s

Built-In Termination: 3-Hour Time-Out

s

C/10 Detection with Status Indicator

s

Automatic Charger Present Detection

s

Automatic Battery Present Detection

s

1- or 2-Cell, 4.1V/Cell or 4.2V/Cell Options

s

Precision Internal 0.2% Voltage Feedback Divider

s

Compatible with LT1505/LT1510/LT1511/

LT1512/LT1513/LT1769

s

Small Footprint/Low Profile

The LTC

controllers for lithium-ion battery chargers. These ICs

provide trickle charge preconditioning, temperature charge

qualification, time or charge current termination, auto-

matic charger and battery detection and status output.

Combining the LTC1729 series part with the LT

(1.5A), LT1769 (2A), LT1511 (3A) and LT1505 (> 4A)

step-down chargers is a simple operation. Connecting six

pins from the LTC1729 series part to the step-down

chargers completes the integration. The LTC1729 termi-

nation controllers are also compatible with step-down/

step-up (SEPIC) chargers, including the LT1512 (2A switch)

and LT1513 (3A switch).

The LTC1729 series is available in the 8-pin MSOP and SO

packages.

s

Cellular Phones

s

PDAs

s

Cradle Chargers

s

Camcorders

Figure 1. 500kHz Li-Ion Cell Phone Charger (0.8A)

Li-Ion Battery Charger

Termination Controllers

October 1999

FEATURES

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

OVP

BAT

SENSE

GND

STATUS

NTC

SW

SENSE

OVP

GND

BOOST

PROG

BAT

1

2

3

4

8

7

6

5

LTC1729-4.2

LT1510-5

1

µF

0.22

µF

L1**

10

µH

0.1

µF

1729 F01

OPTION: TIE RESISTOR TO STATUS FOR

CHARGE TERMINATION AT

LOW CHARGING CURRENT

* TOKIN OR MARCON SURFACE MOUNT

** COILTRONICS TP3-100, 10

µH, 2.2mm HEIGHT

(0.8A CHARGING CURRENT)

COILTRONICS TP1 SERIES, 10

µH, 1.8mm

HEIGHT (<0.5A CHARGING CURRENT)

*** PANASONIC EEFCD1B220

10k NTC THERMISTOR, NTHS1206N02 VISHAY/DALE

NOTE: EITHER A THERMISTOR OR 10k RESISTOR MUST BE PRESENT

0.1

µF

1

µF

1k

22

µF

4.2V

200

Ω

300

Ω

6.19k

+

+

10

µF

MBRM120T3

INPUT POWER

8.2V TO 20V

CHARGE STATUS

MBRM120T3

MMBD914L

1.4k

Final Electrical Specifications

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-

tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.