SC615 Datasheet, PDF (1/12 Pages) Semtech Corporation – Charge Pump Flash LED Driver

POWER MANAGEMENT
Description
Features
SC615
Charge Pump
Flash LED Driver
The SC615 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 SC615 has two modes of operation: Flash mode
and Spotlight mode. The SC615 is capable of delivering
500mA of peak current for a duration of 500ms in Flash
mode. In Spotlight mode the SC615 outputs 100mA
and can remain enabled continuously.
A minimum 0.5Ω sense resistor is used to set the cur-
rent through the LED in both modes. This resistor dissi-
pates up to 0.125W, reducing the power dissipation re-
quirement of the SC615. The flash input (FLASH) over-
rides the control input (CTRL) to make sure the flash func-
tion is activated when called for.
The thermally efficient MLPD-10 package and ceramic
bypass and bucket capacitors help make the SC615 a
high output current driver that requires a minimal amount
of PCB area.
‹ 500mA Output Current - Flash Mode
‹ 3.0V to 5.25V Input Range
‹ Two Selectable Modes - Flash and Spotlight
‹ External Flash Control Pin for Synchronization to a
Camera Module or Graphics Controller
‹ Spotlight Mode Current Setting - 100mA
‹ Short Circuit, Over-Voltage, and Over-Temperature
Protection
‹ Soft-Start Functionality
‹ Two Control Inputs for Maximum Versatility
‹ Shutdown Current < 2µA
‹ Micro Lead-frame Package MLPD-10, 3mm x 3mm
Applications
‹ Mobile Camera Phones
‹ Digital Cameras
‹ PDAs with Built-in Cameras
‹ Multi-LED Backlit LCDs
Application Circuit
3.0V to 5.25V
10µF
1µF
1µF
FLASH
CTRL
SC615
1
9
VIN
VOUT
8
C1+
3
1µF
GND
4
C1-
6
ISET
10
C2+
7
CTRL
2
C2-
5
FLASH
July 11, 2005
1
white LED
0.5Ω
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