LP3945/LP3946 LLP14 Package Drawing

20066503

(TOP VIEW)

See NS Package Number LDA14A

LP3945/LP3946 Pin Description

Pin #

LP3945

LP3946

Description

1

EN

EN

Charger Enable Input. Internally pulled high to CHG-IN pin.

2

SCL

GND

Serial Interface Clock Input for LP3945. Ground in LP3946.

3

SDA

GND

Serial Interface DATA Input/Output for LP3945. Ground in LP3946.

4

BATT

BATT

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

5V

BG

V

BG

Bandgap Voltage Reference (1.225V). Factory test point. Must be left floating.

6VB

SENSE

VB

SENSE

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

7

GND

GND

Digital Ground

8

Diff-Amp

Diff-Amp

Charge current monitoring differential amplifier output. Voltage output representation

of the charge current.

9

BIPB

BIPB

Battery in Place Bar. Input signal to indicate presence/absence of the battery.

Internally pulled high to CHG-IN. Pulled low by the Battery ID resistor. Absence of

the ID resistor (BIPB signal high) indicates no battery. Pulling BIPB pin high sets the

device to LDO mode.

10

EOC

EOC

Active Low Open Drain Output to drive Green LED. Active when wall adaptor is

connected and battery is fully charged. Regardless of the battery chemistry, this

signal is available whenever a battery is attached.

11

GND

GND

Analog Ground

12

CHG

CHG

Active Low Open Drain Output to drive Red LED. Active when wall adaptor is

connected and battery is being charged. Regardless of the battery chemistry, this

signal is available whenever a battery is attached.

13

StopModeEN

StopModeEN

For normal operation, this pin must be left floating. Pulling this pin to ground will

bypass the 5.6 Hrs safety timer in constant current mode. See "StopModeEN PIN"

Section for more detail.

WARNING! Disabling the timer is not a recommended operating condition

since it disables the safety timer function. User must provide protection

against continuously charging a defective battery.

14

CHG-IN

CHG-IN

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

ceramic capacitor to GND.

Ordering Information

LP3945 supplied as 1000 units Tape and Reel

LP3945 supplied as 4500 units Tape and Reel

Package Marking

LP3945ILD

LP3945ILDX

L00011B

LP3946 supplied as 1000 units Tape and Reel

LP3946 supplied as 4500 units Tape and Reel

Package Marking

LP3946ILD

LP3946ILDX

L00030B

The LP3946 has default values of I

Semiconductor Sales Office.

www.national.com

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