4

LTC3490

3490fa

PI FU CTIO S

CELLS (Pin 1): A logic input to set the low-battery and

undervoltage shutdown thresholds. A logic low (tied to

GND) will set the thresholds for 1 cell. A logic high (tied to

SW (Pin 3): Switch Input. Connect this pin to an external

GND (Pin 4): Circuit Ground.

LED (Pin 5): Output Drive Current to LED.

CAP (Pin 6): Filter Capacitor. A 4.7

µF low ESR capacitor

should be tied to this pin.

LOBAT (Pin 7): Low active, open-drain logic output indi-

cating a low-battery condition.

CTRL/SHDN (Pin 8): Analog Control Voltage and Shut-

current varies according to the formula:

I

V

V

mA

LED

CTRL

IN

=

⎛

⎝⎜

⎞

⎠⎟

500

0 2

•– .

power shutdown.

Exposed Pad (Pin 9, DD Package): Ground. This pin must

be soldered to the PCB to provide both electrical contact

to ground and good thermal contact to the PCB.

2.8

340

342

346

348

350

360

354

3

3.2

3.4

3.6

3.8

3490 G04

344

356

358

352

4

TYPICAL PERFOR A CE CHARACTERISTICS

0

0

10

30

40

50

100

70

100

200

3490 G05

20

80

90

60

300

400