SC618
Charge Pump Flash LED
Driver with Safety Timer
POWER MANAGEMENT
Features
Description
Flash and spotlight — two selectable modes
Flash mode — up to 700mA output
Flash mode — 500mA max output (over rated voltage,
temperature, and load conditions)
Flash mode safety timer shut-off — 1 second
Spotlight mode set to 40% of flash current
Spotlight mode — up to 280mA output
Spotlight mode —1x mode (under most conditions)
for best efficiency
The SC618 is a high-current charge pump designed spe-
cifically for use with white LEDs used in camera flash
applications. Only two small bucket capacitors are required
to develop the output drive, providing a low EMI solution
compared to inductive boost regulators.
The SC618 has two modes of operation: flash mode and
spotlight mode. In flash mode, the SC618 is capable of
delivering 500mA of regulated current for a duration of
500ms or up to 700mA for a reduced duration. A safety
timer is also included to ensure the LED cannot be left on
indefinitely and overheat. In spotlight mode the SC618
outputs 40% of the flash mode current and can remain
enabled continuously.
Input range — 3.0V to 5.25V
External flash control pin for synchronization to a cam-
era module or graphics controller
Short-circuit, over-voltage, and over-temperature pro-
tection
Soft-start functionality
Separate flash and spotlight control inputs for maxi-
mum versatility
Ultra-thin package MLPD-UT-10 — 3mm x 3mm x
0.6mm
An external resistor is connected in series with the LED to
set the current. In flash mode, this resistor can dissipate
up to 175mW, reducing the power dissipation require-
ment of the SC618. The flash input overrides the control
input to make sure the flash function is activated .
Applications
The SC618 ultra-thin package provides both a low profile
and high thermal efficiency.
Mobile camera phones
Digital cameras
PDAs with built-in cameras
Typical Application Circuit
SC618
VIN
C1+
C1-
C2+
C2-
VOUT
VBAT
10μF
1μF
GND
White LED
1μF
ISET
CTRL
1μF
RSET
FLASH
FLASH
CTRL
February 6, 2008
1