LM2758 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Switched Capacitor Flash LED Driver in micro SMD

LM2758
October 9, 2009
Switched Capacitor Flash LED Driver in micro SMD
General Description
LM2758 is an integrated low-noise, high-current switched ca-
pacitor DC/DC converter with a regulated current sink. The
device is capable of driving loads up to 700 mA from a single-
cell Li-Ion battery. Maximum efficiency is achieved over the
input voltage range by actively selecting the proper gain
based on the LED forward voltage and current requirements.
One external low-power resistor sets the desired current for
Indicator, Torch and Flash modes. To protect the devices and
the flash LED, internal Time-out circuitry turns off the LM2758
in case of a faulty prolonged Flash mode. Internal soft-start
circuitry limits the amount of inrush current during start-up.
LM2758 is offered in National’s tiny 12-bump thin micro SMD
package.
Features
■ ^{Up to 700 mA Output Current}
■ ^{Ultra-Small Solution Size}
—No Inductor, Only 4 Capacitors and a resistor Required
—1.514 mm x 1.996 mm x 0.6 mm thin micro SMD
package
■ ^{90% Peak Efficiency}
■ ^{Indicator, Torch and Flash Modes}
■ ^{Time-Out Circuitry Limits Flash Duration to 814 msec.}
(typ.)
■ ^{Adaptive 1x and 1.5x Gains for Maximum Efficiency}
■ ^{True Shutdown}
■ ^{Internal Soft-Start Eliminates Inrush Current}
Applications
■ ^{Camera Flash in Mobile Phones}
■ ^{Flash for Digital Cameras}
Typical Application Circuit
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