LM3430 Datasheet, PDF (1/24 Pages) Texas Instruments – Boost Controller for LED Backlighting

January 2007
LM3430
Boost Controller for LED Backlighting
General Description
The LM3430 is a high voltage low-side N-channel MOSFET
controller. Ideal for use in a boost regulator, the LM3430 can
power the LED backlight in LCD panels, such as in notebook
PCs. It contains all of the features needed to implement single
ended primary topologies. Output voltage regulation is based
on current-mode control, which eases the design of loop com-
pensation while providing inherent input voltage feed-forward.
The LM3430 includes a start-up regulator that operates over
a wide input range of 6V to 40V. The PWM controller is de-
signed for high speed capability including an oscillator fre-
quency range up to 2 MHz and total propagation delays less
than 100 ns. Additional features include an error amplifier,
precision reference, line under-voltage lockout, cycle-by-cy-
cle current limit, slope compensation, soft-start, external syn-
chronization capability and thermal shutdown. The LM3430 is
available in the LLP-12 package.
Features
■ ^{Internal 40V Startup Regulator}
■ ^{1A Peak MOSFET Gate Driver}
■ ^V_IN ^{Range 6V to 40V}
■ ^{Duty Cycle Limit in Excess of 90%}
■ ^{Programmable UVLO with Hysteresis}
■ ^{Cycle-by-Cycle Current Limit}
■ ^{External Synchronizable (AC-coupled)}
■ ^{Single Resistor Oscillator Frequency Set}
■ ^{Slope Compensation}
■ ^{Adjustable Soft-start}
■ ^{LLP-12 (3mm x 3mm)}
Applications
■ ^{LED Backlight Driver (companion to LM3432)}
■ ^{Boost Converter}
■ ^{SEPIC Converter}
Typical Application
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