Pin Descriptions

Pin #

Name

Description

1V

IN2

Main Battery Power Input for Buck 2

2

SW2

Buck 2 Switch Pin

3

PGND2

Buck 2 Power Ground

4V

DD

Analog and Digital V

5

SGND

Analog GND

6

PGND1

Buck 1 Power Ground

7

SW1

Buck 1 Switch Pin

8V

IN1

Main Battery Power Input for Buck 1

9

FB1

Analog Feedback Input for Buck 1

10

SDA

I

Ω pull up resistor is required.

11

SCL

I

Ω pull up resistor is required.

12

nPOR1

Power ON Reset for Buck 1, Open drain output Low when Buck 1 output is 92% of

target output. A 100 k

Ω pull up resistor is required

13

nPOR2

Power ON Reset for Buck 2, Open drain output Low when Buck 2 output is 92% of

target output. A 100 k

Ω pull up resistor is required

14

EN1

Buck 1 Enable

15

EN2

Buck 2 Enable

16

FB2

Analog feedback for Buck 2

I

Features

Parameter

Comments

Output Voltage

V

Output voltage is controlled via I

Modes

Buck 1 & Buck 2

Mode can be controlled via I

compatible by either forcing device

in Auto mode or forced PWM mode

Spread Spectrum

Buck 1 & Buck 2

Spread Spectrum capability via I

Ordering Information

Order Number

Voltage Option

Package Marking

Supplied As

LM3370SD-3013*

1.2V & 2.5V

250 units, Tape-and-Reel

LM3370SDX-3013*

3000 units, Tape and Reel

LM3370SD-3021

1.2V & 3.3V

S0003TB

250 units, Tape-and-Reel

LM3370SDX-3021

S0003TB

3000 units, Tape-and-Reel

LM3370SD-3416*

1.4V & 2.8V

250 units, Tape-and-Reel

LM3370SDX-3416*

3000 units, Tape-and-Reel

LM3370SD-4221*

1.8V & 3.3V

250 units, Tape-and-Reel

LM3370SDX-4221*

3000 units, Tape-and-Reel

Note the LM3370SD-3013 has the following default output voltages where V

* Contact National Semiconductor for availability

www.national.com

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