SC615A Datasheet, PDF (1/12 Pages) Semtech Corporation – Charge Pump Flash LED Driver

POWER MANAGEMENT
SC615A
Charge Pump
Flash LED Driver
Description
Features
The SC615A 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 re-
quired to develop the output drive, providing a low EMI
solution compared to inductive boost regulators.
The SC615A has two modes of operation: Flash mode
and Spotlight mode. In Flash mode, the SC615A is ca-
pable of delivering 500mA of regulated current for a du-
ration of 500ms or up to 700mA for a reduced duration.
In Spotlight mode the SC615A outputs 40% of the Flash
mode current and can 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 175mW, reducing the power dissipation
requirement of the SC615A. The flash input (FLASH)
overrides the control input (CTRL) to make sure the flash
function is activated when called for.
‹ Two Selectable Modes - Flash and Spotlight
‹ Up to 700mA Output - Flash Mode
‹ Up to 280mA Output - Spotlight Mode
‹ 500mA Over Temperature Range and Voltage
Range - Flash Mode
‹ Spotlight mode set to 40% of Flash Current
‹ 3.0V to 5.25V Input Range
‹ External Flash Control Pin for Synchronization to a
Camera Module or Graphics Controller
‹ Short Circuit, Over-Voltage, and Over-Temperature
Protection
‹ Soft-Start Functionality
‹ Two Control Inputs for Maximum Versatility
‹ Shutdown Current < 2µA
‹ Micro Lead Package MLPD-10, 3mm x 3mm
Applications
‹ Mobile Camera Phones
‹ Digital Cameras
‹ PDAs with Built-in Cameras
The thermally efficient MLPD-10 package and ceramic
bypass and bucket capacitors make the SC615A a high
output current driver that requires minimal PCB area.
Typical Application Circuit
3.0V to 5.25V
10µF
SC615A
1
9
VIN
VOUT
8
C1+
1µF _C1
4
C1-
3
1µF
GND
6
ISET
10
C2+
1µF _C2
2
C2-
7
CTRL
5
FLASH
white LED
0.5Ω
FLASH
CTRL
September 22, 2005
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