
www.semtech.com
POWER MANAGEMENT
Description
SC605
Charge Pump
Flash LED Driver
December , 2005
Features
of PCB area.
Typical Application Circuit
Applications
Mobile Camera Phones
Digital Cameras
PDAs with Built-in Cameras
The SC605 is a high-current charge pump designed spe-
cifically for use with white LEDs used in camera flash ap
-
plications. Only two small bucket capacitors are required
to develop the output drive, providing a low EMI solution
compared to inductive boost regulators.
The SC605 has two modes of operation: Flash mode and
Spotlight mode. In Flash mode, the SC605 is capable of
delivering 500mA of regulated current for a duration of
500ms or up to 700mA for a reduced duration. In Spotlight
mode the SC605 can output 20%, 30%, or 40% of the Flash
mode current and remain enabled continuously.
An external resistor is connected in series with the LED to
set the current. In Flash mode, this resistor can dissipate
up to 0.75mW, reducing the power dissipation require-
ment of the SC605. The Flash input (FLASH) overrides
the control inputs (CTRL0 and CTRL1) to ensure the Flash
function has the highest priority.
The thermally efficient MLPD-12 package and ceramic
bypass and bucket capacitors help make the SC605 a
high output current driver that requires a minimal amount
Two selectable modes - Flash and Spotlight
Up to 700mA output - Flash mode
Up to 280mA output - Spotlight mode
500mA output over specified temperature and volt
-
age ranges - Flash mode
Spotlight mode selectable to 20%, 30%
and 40% of Flash current
3.0V to 5.25V input range
Flash control pin for synchronization to
a camera module or graphics controller
Short circuit, over-voltage and
over-temperature protection
Soft-start functionality
Three control inputs for maximum versatility
Shutdown current < 2
μ
A
Micro-lead package MLPD-12, 3mm x 3mm
VBAT
0
μ
F
μ
F
white LED
CTRL
CTRL
0
FLASH
0.5
W
SC605
VIN
1
FLASH
6
CTRL0
8
CTRL1
9
NC
5
VOUT
11
ISET
7
C1+
10
C1-
4
C2+
12
C2-
2
μ
F
μ
F
GND
3