LM2759_13 Datasheet, PDF (1/21 Pages) Texas Instruments – LM2759 1A Switched Capacitor Flash LED Driver with I2C Compatible Interface

LM2759
www.ti.com
SNVS577D – JUNE 2008 – REVISED MAY 2013
LM2759 1A Switched Capacitor Flash LED Driver with I²C Compatible Interface
Check for Samples: LM2759
FEATURES
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•2 Up to 1A Output Current
• Solution Area < 22 mm²
• No Inductor Required
• 90% Peak Efficiency
• Adaptive 1x, 1.5x and 2x Gains for Maximum
Efficiency
• Load Disconnect in Shutdown
• Accurate Input Current Control During Gain
Transitions
• Flash Time-Out
• TX Input Pin Ensures Synchronization with RF
Power Amplifier Pulse
• Torch, Flash, and Indicator Modes
• External Flash Enable via Strobe Input Pin
• Strobe Input Disable via I²C
• Programmable Flash Pulse Duration, and
Torch and Flash Currents via I²C-Compatible
Interface
• 1MHz Constant Frequency Operation
• Low Profile 12–Pin WSON (3mm x 3mm x
0.8mm)
APPLICATIONS
• Camera Flash in Cellular Phones
DESCRIPTION
LM2759 is an integrated low-noise, high-current
switched capacitor DC/DC converter with a regulated
current source. The device requires only four small
ceramic capacitors making the total solution area less
than 22 mm² and the height less than 1 mm. The
LM2759 is capable of driving loads up to 1A 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.
The LED current can be programmed up to 1A via an
I²C-compatible interface, along with eight selectable
Flash Time-Out durations. One high-current Flash
LED can be driven either in a high-power Flash mode
or a low-power Torch mode. The Strobe pin allows
the flash to be toggled via a Flash enable signal from
a camera module. The TX input pin limits the Flash
LED current to the Torch current level during a RF
PA pulse, to reduce high loads on the battery.
Internal soft-start circuitry limits the amount of inrush
current during start-up.
LM2759 is offered in a small 12-pin thermally
enhanced WSON package.
Typical Application Circuit
V_IN = 3.0V - 5.5V
V_IN
C₁+
C_IN
2.2 µF
C₁
2.2 µF
V_OUT
I_LED = Up to 1A
4.7 µF
C_{OUT D1}
C₁-
C₂+
I_SINK
LM2759
C₂
2.2 µF
C₂-
SDA
SCL
Strobe
TX
GND
TDK: 2.2 µF ± C1608X5R1C225
4.7 µF ± C2012X5R1C475
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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