Datasheet Texas Instruments LM3434SQ/NOPB — Ficha de datos

LM3434
www.ti.com SNVS619B – MARCH 2010 – REVISED MAY 2013 Common Anode Capable High Brightness LED Driver with High Frequency Dimming
Check for Samples: LM3434 FEATURES DESCRIPTION The LM3434 is an adaptive constant on-time DC/DC
buck (step-down) constant current controller (a true
current source). The LM3434 provides a constant
current for illuminating high power LEDs. The output
configuration allows the anodes of multiple LEDs to
be tied directly to the ground referenced chassis for
maximum heat sink efficacy. The high frequency
capable architecture allows the use of small external
passive components and no output capacitor while
maintaining low LED ripple current. Two control
inputs are used to modulate LED brightness. An
analog current control input is provided so the
LM3434 can be adjusted to compensate for LED
manufacturing variations and/or color temperature
correction. The other input is a logic level PWM
control of LED current. The PWM functions by
shorting out the LED with a parallel switch allowing
high PWM dimming frequencies. High frequency
PWM dimming allows digital color temperature
control, interference blanking, field sequential
illumination, and brightness control. Additional …