LP5526
Lighting Management Unit with High Voltage Boost
Converter with up to 150mA Serial FLASH LED Driver
General Description
LP5526 is a Lighting Management Unit for portable applica-
tions. It is used to drive display backlights, keypad LEDs,
RGB LEDs and camera flash LEDs. LP5526 can drive 2
separately connected strings of LEDs with high voltage
boost converter. The RGB driver allows driving either indi-
vidual color LEDs or RGB LED from separate supply power,
or it can be used to drive series connecter flash LEDs from
high voltage boost converter.
The backlight drivers (MAIN and SUB pins) are both high
resolution constant current mode drivers. The flash outputs
can drive series connected flash LED with up to 150mA of
current. External PWM control can be used for dimming any
selected LED outputs or it can be used to trigger the flash.
The flash has also 1-second safety timer.
The device is controlled through 2-wire low voltage I
2
C
compatible interface that reduces the number of required
connections.
Features
n
High efficiency boost converter with programmable
output voltage up to 20V
n
2 individual drivers for serial display backlight LEDs
n
Automatic dimming controller
n
Stand alone RGB controller
n
Dedicated flash function
n
Safety function to avoid prolonged flash
n
3 general purpose IO pins
n
25-bump micro SMD Package: (2.54mm x 2.54mm x
0.6mm)
Applications
n
Cellular Phones and PDAs
n
MP3 Players
n
Digital Cameras
Typical Application
20179770
March 2006
LP5526
Lighting
Management
Unit
with
High
V
oltage
Boost
Converter
with
up
to
150mA
Serial
FLASH
LED
Driver
2006 National Semiconductor Corporation
DS201797
www.national.com
Pin Descriptions
Pin #
Name
Type
Description
5E
SW
Output
Boost Converter Power Switch
5D
FB
Input
Boost Converter Feedback
5C
RLED
Output
Red LED Output (Current Sink / Open Drain Switch)
5B
GLED
Output
Green LED Output (Current Sink / Open Drain Switch)
5A
BLED
Output
Blue LED Output (Current Sink / Open Drain Switch)
4E
GND_SW
Ground
Power Switch Ground
4D
NRST
Input
External Reset, Active Low
4C
SCL
Logic Input
Clock Input for I
2
C Compatible Interface
4B
IRGB
Input
External RGB LED Maximum Current Set Resistor
4A
GND_RGB
Ground
Ground for RGB LED Currents
3E
VDD2
Power
Supply Voltage 3.0...5.5 V
3D
VDDIO
Power
Supply Voltage for Digital Input/Output Buffers and Drivers
3C
SDA
Logic Input/Output
Data Input/Output for I
2
C Compatible Interface
3B
GPIO[2]
Logic Input/Output
General Purpose Logic Input/Output
3A
GPIO[0] / PWM
Logic Input/Output
General Purpose Logic Input/Output / External PWM Input
2E
GND_WLED
Ground
Ground for White LED Currents (MAIN and SUB Outputs)
2D
GNDT
Ground
Ground
2C
VDD1
Power
Supply Voltage 3.0...5.5 V
2B
VREF
Output
Reference Voltage (1.23V)
2A
GPIO[1]
Logic Input/Output
General Purpose Logic Input/Output
1E
MAIN
Output
MAIN Display White LED Current Output (Current Sink)
1D
SUB
Output
SUB Display White LED Current Output (Current Sink)
1C
VDDA
Output
Internal LDO Output (2.80V)
1B
GND
Ground
Ground for Core Circuitry
1A
IRT
Input
Oscillator Frequency Set Resistor
Package Mark
20179796
Ordering Information
Order Number
Package Marking
Supplied As
Spec/Flow
LP5526TL
5526
TNR 250
NoPb
LP5526TLX
5526
TNR 3000
NoPb
LP5526
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3
Absolute Maximum Ratings
(Notes 1,
2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
V (SW, FB, MAIN, SUB, RLED,
GLED, BLED)
-0.3V to +23V
V
DD1
, V
DD2
, V
DDIO
, V
DDA
-0.3V to +6.0V
Voltage on I
RGB
, I
RT
, V
REF
-0.3V to V
DD1
+0.3V
with 6.0V max
Voltage on Logic Pins
-0.3V to V
DDIO
+0.3V
with 6.0V max
I (V
REF
)
10A
I(RLED, GLED, BLED)
100mA
Continuous Power Dissipation
(Note 3)
Internally Limited
Junction Temperature (T
J-MAX
)
125
o
C
Storage Temperature Range
-65
o
C to +150
o
C
Maximum Lead Temperature
(Soldering) (Note 4)
260
o
C
ESD Rating (Note 5)
Human Body Model:
2kV
Machine Model:
200V
Operating Ratings
(Notes 1, 2)
V (SW, FB, MAIN, SUB)
0 to +21V
V
DD1,2
3.0 to 5.5V
V
DDIO
1.65V to V
DD1
Recommended Load Current
(RLED, GLED, BLED) CC Mode
0mA to 50mA/driver
Recommended Total Boost
Converter Load Current
0mA to 150mA
Junction Temperature (T
J
) Range
-30
o
C to +125
o
C
Ambient Temperature (T
A
) Range
(Note 6)
-30
o
C to +85
o
C
Thermal Properties
Junction-to-Ambient Thermal
Resistance(
JA
), TLA25 Package
(Note 7)
60 - 100
o
C/W
LP5526
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4
Electrical Characteristics
(Notes 2, 8)
Limits in standard typeface are for T
J
= 25
o
C. Limits in boldface type apply over the operating ambient temperature range
(-30
o
C
<
T
A
<
+85
o
C). Unless otherwise noted, specifications apply to the LP5526 Block Diagram with: V
DD1,2
= 3.0 ... 5.5V,
C
VDD
= C
VDDIO
= 100nF, C
OUT
= 2 x 4.7F, C
IN
= 10F, C
VDDA
= 1F, C
VREF
= 100nF, L1 = 10H, R
RGB
= 2.4k
and R
RT
=
82k
(Note 9).
Symbol
Parameter
Condition
Min
Typ
Max
Units
I
VDD
Standby supply current
(V
DD1
, V
DD2
)
NSTBY = L
Register 0DH=08H (Note 10)
1.7
7
A
No-boost supply current
(V
DD1
, V
DD2
)
NSTBY = H,
EN_BOOST = L
300
800
A
No-load supply current
(V
DD1
, V
DD2
)
NSTBY = H, EN_BOOST = H
Autoload OFF
780
1300
uA
V
DDA
Output voltage of internal LDO
I
VDDA
= 1mA
2.80
V
-3
+3
%
V
REF
Reference voltage (Note 11)
1.23
V
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Operating Ratings are conditions under which operation of
the device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the
Electrical Characteristics tables.
Note 2: All voltages are with respect to the potential at the GND pins.
Note 3: Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at T
J
=150
o
C (typ.) and disengages at
T
J
=130
o
C (typ.).
Note 4: For detailed soldering specifications and information, please refer to National Semiconductor Application Note AN1112 : Micro SMD Wafer Level Chip Scale
Package
Note 5: The Human body model is a 100pF capacitor discharged through a 1.5k
resistor into each pin. The machine model is a 200pF capacitor discharged
directly into each pin. MIL-STD-883 3015.7
Note 6: In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may have to be
derated. Maximum ambient temperature (T
A-MAX
) is dependent on the maximum operating junction temperature (T
J-MAX-OP
= 125
o
C), the maximum power
dissipation of the device in the application (P
D-MAX
), and the junction-to ambient thermal resistance of the part/package in the application (
JA
), as given by the
following equation: T
A-MAX
= T
J-MAX-OP
(
JA
x P
D-MAX
).
Note 7: Junction-to-ambient thermal resistance is highly application and board-layout dependent. In applications where high maximum power dissipation exists,
special care must be paid to thermal dissipation issues in board design.
Note 8: Min and Max limits are guaranteed by design, test, or statistical analysis. Typical numbers are not guaranteed, but do represent the most likely norm.
Note 9: Low-ESR Surface-Mount Ceramic Capacitors (MLCCs) used in setting electrical characteristics.
Note 10: Boost output voltage set to 8V (08H in register 0DH) to prevent any unneccessary current consumption.
Note 11: No external loading allowed for V
REF
pin.
LP5526
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