SC4541
High Frequency LED Driver with
POWER MANAGEMENT
Features
Integrated Schottky and Simple Interconnect
Description
VIN Range — 2.9V to 22V
VOUT Range — Up to 25V
IOUT Range:
Up to 100mA (Boost)
Up to 200mA (Buck)
Drives Up to 7 Series WLEDs (Boost)
Drives Up to 5 Series WLEDs (Buck)
Integrated Schottky Rectifier
Single-Wire LED Connect
Current Mode Control
Frequency — 2.0MHz
No External Compensation
Direct PWM Dimming
100:1 Range at 500Hz
Open-LED Protection — 27V
Low Shutdown Current < 1µA
Package Options:
Low Profile MLPD-UT, 6-pin 2x2 x0.6(mm)
SOT23, 6-pin 2.9x2.8 x1.45(mm)
Lead-free, Halogen-Free and WeEE/RoHS Compliant
Applications
Keypad Illumination
DSC and DSLR Display Backlight
Cellular Handsets
Automotive Lighting
The SC4541 is a fully integrated, high voltage boost (step-
up) and buck (step-down) LED driver. The input voltage
range is 2.9V to 22V with output voltage up to 25V. The
device is capable of driving up to 7 white LEDs. The high
side sense enables a single-wire LED connection by taking
advantage of the available system ground. This reduces
connector cost and complexity.
The device includes a current mode PWM controller,
260mA power switch, and high performance Schottky
rectifier. The LED driver eliminates external compensation
components for minimum solution size.
The wide input voltage range and low standby current are
ideal for portable devices. The high input voltage allows
direct connection to multi-cell battery packs which
increases operating efficiency and extends battery life.
Output current is programmed with an external sense
resistor up to 100mA (Boost) or 200mA (Buck). The device
provides ±5% constant current accuracy across the entire
operating temperature range.
A logic level PWM dimming signal may be applied directly
to the enable (EN) pin - for direct PWM dimming with a
wide dimming range. Output OVP (over voltage protec-
tion) protects the SC4541 from open circuit faults in the LED
string or connector. External OVP programming resistors
are not required.
The SC4541 is available in low profile MLPD-UT and
SOT23,6-pin packages. The device is rated across the
temperature range -40°C to +85°C.
Typical Application Circuit
VIN 2.9V to 22V
Boost Topology IOUT up to 100mA
L1
C1
10μF
1μF
IN
SW OUT VOUT Up to 25V
SC4541
C2
1μF
RS
10Ω
PWM
Dimming
EN GND FB
7 WLED @
20mA
Version 1.3
© 2011 Semtech Corporation
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