Connection Diagrams and Package Mark Information

20111002

(Top View)

See NS Package Number SDA14B

Pin Description

Pin #

Name

Description

1

EN

Charger Enable Input. Internally pulled high to CHG-IN pin. A HIGH enables the charger and a

LOW disables the charger.

2

SCL

I

3

SDA

I

4

BATT

Battery supply input terminal. Must have 10 µF ceramic capacitor to GND

5V

T

Regulated 2.78V output used for biasing the battery temperature monitoring thermistor.

6VB

SENSE

Battery Voltage Sense connected to the positive terminal of the battery.

7

MODE

Select pin between AC adaptor and USB port. A LOW sets the LP3947 in USB port and a HIGH

sets it in the AC adaptor.

8

Diff-Amp

Charge current monitoring differential amplifier output. Voltage output representation of the charge

current.

9

Ts

Multi function pin. Battery temperature monitoring input and LDO/Charger mode.

Pulling this pin to V

device in LDO mode.

10

EOC

Active Low Open Drain Output. Active when USB port or AC adaptor is connected and battery is

fully charged. For more information, refer to “LED Charge Status Indicators” section.

11

GND

Ground

12

CHG

Active Low Open Drain Output. Active when USB port or AC adaptor is connected and battery is

being charged. For more information, refer to “LED Charge Status Indicators” section.

13

ISEL

Control pin to switch between low power (100 mA) mode and high power (500 mA) mode in USB

mode. This pin is pulled high internally as default to set the USB in 100 mA mode. This pin has to

be externally pulled low to go into 500 mA mode.

14

CHG-IN

Charger input from a regulated, current limited power source. Must havea1µF ceramic capacitor

to GND

Ordering Information

LP3947

Supplied as 1000 Units,

Tape and Reel

LP3947

Supplied as 4500 Units

Tape and Reel

Default

Options*

Package

Marking

LP3947ISD-09

LP3947ISDX-09

I

V

EOC = 0.1C

L00055B

LP3947ISD-51

LP3947ISDX-51

I

V

EOC = 0.1C

L00056B

*Other default options are available. Please contact National Semiconductor sales office/distributors for availability and specifications.

www.national.com

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