Preliminary Datasheet

LP3390

LP3390 Version 1.0 Datasheet

NOV.-2013

www.lowpowersemi.com

Page 2 of 8

Functional Pin Description

Pin Number

Pin Name

Pin Function

1

GND

Ground Pin

2

VIN2

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

noise.

3

EN2

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.

4

FB1

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. FB voltage is 200mV.

5

SW1

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

area to reduce EMI.

6

VIN1

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

noise.

7

OVP

OVP Pin. Overvoltage Sense. When VOUT is greater than 29V, the internal

N-channel MOSFET turns off until VOUT drops below 29V, then the IC reenters

start. Connect a 1uF capacitor from OUT to GND

8

EN1

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.

9

FB2

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. FB voltage is 1250mV.

10

SW2

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

area to reduce EMI.