White LED Step-Up Converter

LM1938

Aug. 2011 – Pre

- 2

-

HTC

Ordering Information

Package

Order No.

Package Marking

Supplied As

Status

SOT-23 6L

LM1938SF6

LM1938

Reel

Active

PIN CONFIGURATION

SW

GND

FB

OVP

Vin

/SHDN

SOT-23-6

1

2

34

5

6

PIN DESCRIPTION

SOT-23-6L

Pin No.

Name

Function

1

SW

Switching Pin. This is the collector of the internal NPN power switch.

Connect to inductor and diode. Minimize the metal trace area

connected to this pin to reduce EMI.

2

GND

Ground Pin. Connect directly to local ground plane.

3

FB

Feedback Pin. Reference voltage is 95mV.

Connect LEDs and a resistor at this pin.

4

SHDN

Shutdown Pin. Connect to 1.5V or higher to enable device; 0.4V or less

to disable device.

5

OVP

Over voltage protection, 29.

6

Vin

Input Supply Pin. Bypass this pin with a capacitor as close to the device

as possible.