FSP3301 Datasheet, PDF (1/9 Pages) FOSLINK SEMICONDUCTOR CO.,LTD – FIXED FREQUENCY WHITE LED DRIVER

„ FEATURES
z On Board Power Transistor
z Drives up to 6 Series White LEDs
z Up to 87% Efficiency
z Over 1 MHz Fixed Switching Frequency
z Open Load protection
z Low 104mV Feedback Voltage
z PWM Dimming
z UVLO
z Internal Current Limit
z Available in TSOT23-6L and QFN8L Packages
„ APPLICATIONS
z Cell Phones
z Handheld Computers and PDAs
z Digital Still Cameras
z Small LCD Displays
„ PIN CONFIGURATION
(1) TSOT23-6L
(Top View)
FIXED FREQUENCY WHITE LED DRIVER
FSP3301
„ GENERAL DESCRIPTION
The FSP3301 is a step-up converter designed for
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.
(2) QFN8L
(Top View)
Symbol
TSOT23-6L QFN8L
1
8
2
1，5
3
6
4
4
5
3
6
2
Name
SW
GND
FB
EN
OV
IN
Descriptions
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.
Ground.
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.
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.
Over Voltage Input. OV measures the output voltage for open circuit protection.
Connect OV to the output at the top of the LED string.
Input Supply Pin. Must be locally bypassed.
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2007-4-16