LM3405AXMY Datasheet, PDF (1/32 Pages) Texas Instruments – LM3405A 1.6MHz, 1A Constant Current Buck LED Driver with Internal ensation in Tiny SOT and VSSOP PowerPAD Packages

LM3405A
www.ti.com
SNVS508C – OCTOBER 2007 – REVISED MAY 2013
LM3405A 1.6MHz, 1A Constant Current Buck LED Driver with Internal Compensation in
Tiny SOT and VSSOP PowerPAD Packages
Check for Samples: LM3405A
FEATURES
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•2 V_IN Operating Range of 3V to 22V
• Drives up to 5 High-Brightness LEDs in Series
at 1A
• Thin SOT-6 package and VSSOP-8 PowerPAD
Packages
• 1.6MHz Switching Frequency
• EN/DIM Input for Enabling and PWM Dimming
of LEDs
• 300mΩ NMOS Switch
• 40nA Shutdown Current at V_IN = 5V
• Internally Compensated Current-mode Control
• Cycle-by-cycle Current Limit
• Input Voltage UVLO
• Over-current Protection
• Thermal Shutdown
DESCRIPTION
The LM3405A is a 1A constant current buck LED
driver designed to provide a simple, high efficiency
solution for driving high power LEDs. With a 0.205V
reference voltage feedback control to minimize power
dissipation, an external resistor sets the current as
needed for driving various types of LEDs. Switching
frequency is internally set to 1.6MHz, allowing small
surface mount inductors and capacitors to be used.
The LM3405A utilizes current-mode control and
internal compensation offering ease of use and
predictable, high performance regulation over a wide
range of operating conditions. With a maximum input
voltage of 22V, it can drive up to 5 High-Brightness
LEDs in series at 1A forward current, with the single
LED forward voltage of approximately 3.7V.
Additional features include user accessible EN/DIM
pin for enabling and PWM dimming of LEDs, thermal
shutdown, cycle-by-cycle current limit and over-
current protection.
APPLICATIONS
• LED Driver
• Constant Current Source
• Industrial Lighting
• LED Flashlights
• LED Lightbulbs
TYPICAL APPLICATION CIRCUIT
D3
D2
Efficiency vs LED Current (V_IN = 12V)
V_IN
C1
ON
OFF
V_IN
BOOST
C3
SW
LM3405A
D1
EN/DIM
FB
GND
L1
V_OUT
C2 C4
I_F
R1
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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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