FIXED FREQUENCY WHITE LED DRIVER

FSP3301

2007-4-16

1/9

PIN CONFIGURATION

(1) TSOT23-6L

(2) QFN8L

(Top View)

(Top View)

Symbol

TSOT23-6L

QFN8L

Name

Descriptions

1

8

SW

Power Switch Output. SW is the drain of the internal MOSFET switch. Connect

the power inductor and output rectifier to SW. SW can swing between GND and

29V.

2

1，5

GND

Ground.

3

6

FB

Feedback Input. The FSP3301 regulates the voltage across the current sense

resistor between FB and GND. Connect a current sense resistor from the

bottom of the LED string to GND. Connect the bottom of the LED string to FB.

The regulation voltage is 104mV.

4

4

EN

Regulator On/Off Control Input. A high input at EN turns on the converter, and a

low input turns it off. When not used, connect EN to the input source for

automatic startup. The EN pin cannot be left floating.

5

3

OV

Over Voltage Input. OV measures the output voltage for open circuit protection.

Connect OV to the output at the top of the LED string.

6

2

IN

Input Supply Pin. Must be locally bypassed.

FEATURES

On Board Power Transistor

Drives up to 6 Series White LEDs

Up to 87% Efficiency

Over 1 MHz Fixed Switching Frequency

Open Load protection

Low 104mV Feedback Voltage

PWM Dimming

UVLO

Internal Current Limit

Available in TSOT23-6L and QFN8L Packages

GENERAL DESCRIPTION

driving up to 6 series white LEDs from a single cell

Lithium Ion battery. The FSP3301 uses current mode,

fixed frequency architecture to regulate the LED

current, which is measured through an external

current sense resistor. Its low 104mV feedback

voltage reduces power loss and improves efficiency.

The OV pin monitors the output voltage and hold the

output voltage equal Vov if an over-voltage condition

is present due to an open circuit condition.

The FSP3301 includes under-voltage lockout, current

limiting and thermal overload protection preventing

damage in the event of an output overload.

The FSP3301 is available in small 6-pin TSOT23 or

8-pin QFN (2mm x 2mm) packages.

APPLICATIONS

Cell Phones

Handheld Computers and PDAs

Digital Still Cameras

Small LCD Displays