Preliminary Datasheet

LP3311S

LP3311s – 02 Version 2.0 Datasheet

May.-2013

www.lowpowersemi.com

Page 2 of 7

Functional pin description

SOT-23-6

Pin Name

Pin Function

1

SW

Switch Pin. Connect this Pin to inductor and catch diode. Minimize the

track area to reduce EMI.

2

GND

Ground Pin

3

FB

Feedback Reference Voltage Pin. Series connect a resistor between

WLED and ground as a current sense. Sense the current feedback

voltage to set the current rating.

4

EN

Chip Enable (Active High). Voltage sensing input to trigger the function of

over voltage protection. Note that this pin is high impedance. There

should be a pull low 100kΩ resistor connected to GND when the control

signal is floating.

5

OVP

Over voltage pin.

6

Vin

Supply Input Voltage Pin. Bypass 1uF capacitor to GND to reduce the

input noise.

Function Block Diagram

SLOPE

1MHz

OBCILLATOR

ENABLE

4mS

DELAY

Over

voltage

∑

OTA

Soft

start

PWM_COMP.

R

S

Q

PWM

RS

200 mV

IN

OUT

SW

FB

EN

GND