LM3555TLE Datasheet, PDF (1/33 Pages) Texas Instruments – LM3555 Synchronous Boost Converter with 500 mA High Side LED Driver and Dual-Mode Control Interface

LM3555
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SNVS594E – JANUARY 2009 – REVISED NOVEMBER 2011
LM3555 Synchronous Boost Converter with 500 mA High Side LED Driver and Dual-Mode
Control Interface
Check for Samples: LM3555
FEATURES
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•2 High-Voltage High-Side Current Source Allows
for Grounded Cathode LED Operation
• Synchronous Boost Converter
• Peak Converter Efficiency >90%
• Accurate and Programmable LED Current
ranging from 60 mA to 500 mA
• Adaptive LED Current Range Based on LED
Configuration
• Dedicated Indicator Current Source
• Dedicated Torch and Strobe Pins
• Dual Mode Control (General Purpose or I²C)
• Broken Inductor Detection
• Output Over-Voltage Protection
• Output and LED Short-Circuit Protection
• 400kHz I²C-Compatible Interface
• 12-Bump, 1.575 mm x 2.1 mm x 0.6 mm micro
SMD Package (TLA12BCA)
APPLICATIONS
• Camera Phone LED Flash
DESCRIPTION
The LM3555 is a 2 MHz fixed frequency, current mode synchronous boost converter designed to drive either a
single flash LED at 500 mA or two series flash LEDs at 400 mA. A high-voltage current source allows the LEDs
to be terminated to the GND plane eliminating the need for an additional return trace back to the IC.
A dual mode control interface allows the user to configure the LM3555 with a general-purpose interface using
two enable pins for control or an I²C allowing a higher level of control. Both interfaces allow access to the
indicator, assist light and flash modes. A dedicated Strobe pin provides a direct interface to trigger the flash
event, while an external Torch pin provides an additional method for enabling the LEDs in a constant current
mode.
The LM3555 can adaptively scale the maximum flash level delivered to the LED/LEDs based upon the flash
configuration, whether it be a single LED or two LEDs in series.
Eight protection features are available on the LM3555 ranging from over-voltage protection to broken inductor
detection. The LM3555 has four selectable inductor current limits to help the user select an inductor that is
appropriate for the design.
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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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