Preliminary Datasheet
High Performance, Constant Current Switching
Regulator For White LED
General Description
The LP3302S is a 1.1MHz PWM boost switching
regulator designed for constant- current white LED
driver applications. The LP3302S can drive a string
of up to 8 white LEDs from a 3.3V supply or 3S9P
white LEDs from a 5V supply in series, ensuring
uniform brightness and eliminating several ballast
resistors. The LP3302S implements a constant
frequency 1.1MHz PWM control scheme. The high
frequency PWM operation also saves board space
by reducing external component sizes. 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.
LP3302S
Features
High Efficiency: 88%
1.1MHz Fixed-Frequency PWM Operation
Maximum Output Voltage up to 27.5V
Operating Range : 2.7V to 6V
Shutdown Supply Current:<1uA
Available in T/SOT23-6 Package
Built-in Over Voltage Protection
Minimize the External Component
RoHS Compliant and 100% Lead Pb-Free
Applications
WLED Backlight driver
OLED Backlight driver
PDA
DSC
Camera Flash WLED driver
Ordering Information
LP3302S
Typical Application Circuit
Vin
4.7uH
1
+
1uF
1uF
+
F:Pb-free
J6:TSOT23-6
B6: SOT23-6
6
LX
Vin
OUT
5
EN
GND
4
FB
3
LP3302S
2
Pin Configurations
Marking information
Please view website
.
SOT23-6/TSOT23-6
LP3302S –02
Version 1.2 Datasheet
Feb.-2012
www.lowpowersemi.com
Page 1 of 11
Preliminary Datasheet
Application Circuit
Vin
4.7uH
+
2.2uF
6
Vin
1
2.2uF
OUT
5
6
Vin
+
2.2uF
Vin
Panel
4.7uH
+
1
2.2uF
OUT
5
+
LP3302S
Panel
LX
EN
GND
4
FB
3
EN
GND
4
LX
FB
3
LP3302S
2
LP3302S
2
LP3302 for 6pcs Application Circuit
Vin
4.7uH
+
1
2.2uF
6
Vin
2.2uF
OUT
5
+
Rset
12
Rset
5.1
LP3302 for 2X6pcs Application Circuit
Vin
4.7uH
+
2.2uF
6
Vin
1
2.2uF
OUT
5
+
Panel
Panel
LX
GND
EN
FB
EN
GND
4
3
4
LX
FB
3
LP3302S
2
2
LP3302S
LP3302 for 7pcs Application Circuit
Rset
12
Rset
5.1
LP3302 for 2X7pcs Application Circuit
Vin
4.7uH
+
2.2uF
6
Vin
1
2.2uF
OUT
5
+
Panel
EN
GND
4
LX
FB
3
LP3302S
2
LP3302 for 21pcs Application Circuit
Rset
2
LP3302S –02
Version 1.2 Datasheet
Feb.-2012
www.lowpowersemi.com
Page 2 of 11
Preliminary Datasheet
Functional pin description
SOT-23-6
TSOT23-6
1
2
3
Pin Name
LX
GND
FB
Pin Function
LP3302S
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 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 27.5V, the internal
N-channel MOSFET turns off until VOUT drops below 27V, then the IC reenters
start. Connect a 1uF capacitor from OUT to GND.
Supply Input Voltage Pin. Bypass 1uF capacitor to GND to reduce the input
noise.
4
EN
5
6
OUT
VIN
Function Block Diagram
LP3302S –02
Version 1.2 Datasheet
Feb.-2012
www.lowpowersemi.com
Page 3 of 11
Preliminary Datasheet
Absolute Maximum Ratings
LP3302S
Supply Input Voltage---------------------------------------------------------------------------------------------------−0.3V to 6.5V
LX Input Voltage --------------------------------------------------------------------------------------------------------−0.3V to 36V
OVP Voltage--------------------------------------------------------------------------------------------------------------−0.3V to 28V
The Other Pins ----------------------------------------------------------------------------------------------------------−0.3V to 5.5V
Power Dissipation, P
D
@ T
A
= 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
Electrical Characteristics
Parameter
System Supply Input
Operation voltage Range
Under Voltage Lock Out
Supply Current
Shut Down Current
Line Regulation
Oscillator
Operation Frequency
Maximum Duty Cycle
Dimming Frequency
Feedback Voltage
MOSFET
On Resistance of MOSFET
Protection
OVP Threshold
OVP Sink Current
OCP
Shut Down Voltage
Enable Voltage
V
EN
V
EN
1.5
V
OVP
R
DS(ON)
0.8
Ω
LP3302S
F
OSC
V
DD
V
DD
I
DD
I
DD
FB=0V, Switching
V
EN
< 0.4V
V
IN
: 3.0~4.3V
2.7
2.4
0.8
0.1
3
1.3
1
6
V
V
mA
uA
%
MHz
Symbol
Test Condition
Min
Typ.
Max
Units
0.8
89
100
235
1.1
92
96
100k
%
Hz
mV
250
270
27.5
5
850
29
V
μA
mA
0.4
V
V
LP3302S –02
Version 1.2 Datasheet
Feb.-2012
www.lowpowersemi.com
Page 4 of 11
Preliminary Datasheet
Typical Operating Characteristics
LP3302S
LP3302S –02
Version 1.2 Datasheet
Feb.-2012
www.lowpowersemi.com
Page 5 of 11
Microchip MCU
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
