Preliminary Datasheet
LP3302
High Performance, Constant Current Switching
Regulator For White LED
General Description
The LP3302 is a 1.1MHz PWM boost switching regulator
designed for constant current white LED driver applications.
The LP3302 can drive a string of up to 8 white LEDs from a
3.2V supply or 21 white LEDs from a 5V supply in series,
ensuring uniform brightness and eliminating several ballast
resistors. The LP3302 implements a constant frequency
1.1MHz PWM control scheme. The high frequency PWM
operation also saves board space by reducing external
component size. To improve efficiency, the feedback
voltage is set to 250mV, which reduces the power
dissipation in the current setting resistor.
Highly integration and internal compensation network
minimizes as 5 external component counts. Optimized
operation frequency can meet the requirement of small LC
filters value and low operation current with high efficiency.
Features
High Efficiency: 88%
1.1MHz Fixed-Frequency PWM Operation
Maximum Output Voltage up to 29V
Operating Range : 2.7V to 6V
Shutdown Supply Current:<1uA
Available in SOT23-6 Package
Built-in Over Voltage Protection
Minimize the External Component
RoHS Compliant and 100% Lead Pb-Free
Pin Configurations
Ordering Information
LP3302
F:Pb-free
Package Type
B6:SOT23-6
Applications
WLED Backlight driver
OLED Backlight driver
PDA
DSC
Camera Flash WLED driver
LP3302B6F-00
Version 1.0 Datasheet
May.-2013
www.lowpowersemi.com
Page 1 of 13
Preliminary Datasheet
LP3302
Typical Application Circuit
Vin
10uH
1
Cin
10uF
6
SS14
Cout
1uF
LX
Vin
OVP
5
PWM
EN
GND
4
FB
3
0-100KHz
2
LP3302B6F
R1
12
Marking information
Device
LP3302B6F
Marking
LPS
F3XXX
Package
SOT23-6
Shipping
3K/REEL
LP3302B6F-00
Version 1.0 Datasheet
May.-2013
www.lowpowersemi.com
Page 2 of 13
Preliminary Datasheet
LP3302
Application Circuit
Vin
Vin
10uH
+
2.2uF
6
Vin
1
2.2uF
6
5
4
EN
GND
4
FB
3
Vin
OVP
+
2.2uF
Panel
10uH
+
1
2.2uF
OVP
5
+
Panel
LX
LX
EN
GND
FB
3
2
LP3302
2
LP3302
LP3302 for 4pcs Application Circuit
Vin
10uH
+
1
2.2uF
6
Vin
2.2uF
OVP
5
+
Rset
12
Rset
5.1
LP3302 for 2X6pcs Application Circuit
Vin
10uH
+
2.2uF
6
Vin
1
2.2uF
OVP
5
+
Panel
Panel
LX
GND
EN
FB
EN
GND
4
3
4
LX
FB
3
2
LP3302
2
LP3302
LP3302 for 7pcs Application Circuit
Rset
12
Rset
5.1
LP3302 for 2X7pcs Application Circuit
Vin
10uH
+
1
2.2uF
6
Vin
2.2uF
OVP
5
+
Panel
EN
GND
4
LX
FB
3
2
LP3302
LP3302 for 21pcs Application Circuit
Rset
2
LP3302B6F-00
Version 1.0 Datasheet
May.-2013
www.lowpowersemi.com
Page 3 of 13
Preliminary Datasheet
LP3302
Functional pin description
SOT-23-6
1
2
3
Pin Name
LX
GND
FB
Pin Function
Switch Pin. Connect this Pin to inductor and catch diode. Minimize the track
area to reduce EMI.
Ground Pin
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.
Chip Enable (Active High). Voltage sensing input to trigger the function of
4
EN
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.
OVP Pin. Overvoltage Sense. When VOUT is greater than 29V, the internal
5
OUT
N-channel MOSFET turns off until VOUT drops below 29V, then the IC
reenters start. Connect a 1uF capacitor from OUT to GND.
6
VIN
Supply Input Voltage Pin. Bypass 1uF capacitor to GND to reduce the input
noise.
LP3302B6F-00
Version 1.0 Datasheet
May.-2013
www.lowpowersemi.com
Page 4 of 13
Preliminary Datasheet
LP3302
Function Block Diagram
IN
OUT
LX
250mV
FB
PWM_COMP.
R
Q
S
PWM
1
4mS
DELAY
SLOPE
EN
ENABLE
1.1MHz
OBCILLATOR
GND
Absolute Maximum Ratings
Supply Input Voltage---------------------------------------------------------------------------------------------------−0.3V to 6.5V
LX Input Voltage --------------------------------------------------------------------------------------------------------−0.3V to 36V
OVP Voltage--------------------------------------------------------------------------------------------------------------−0.3V to 27V
The Other Pins ----------------------------------------------------------------------------------------------------------−0.3V to 5.5V
Power Dissipation, PD @ TA = 25°C SOT-23-6 ------------------------------------------------------------------------0.455W
Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------------ 260°C
Operation Temperature Range -------------------------------------------------------------------------------------−40°C to 80°C
Storage Temperature Range --------------------------------------------------------------------------------------−65°C to 150°C
LP3302B6F-00
Version 1.0 Datasheet
May.-2013
www.lowpowersemi.com
Page 5 of 13