LM3433 LED Driver

LM3433 – PowerWise® Common Anode Capable High-Brightness LED Driver with High-Frequency Dimming

Image of Texas Instruments' LM3433 LED DriverTexas Instruments' LM3433 is an adaptive constant-on-time DC/DC buck constant current controller. It 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 efficiency. 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 provided for LED brightness control. An analog current control input is provided so the LM3433 can be adjusted to compensate for LED manufacturing variations and/or color temperature correction. The other input is a logic level pulse width modulation (PWM) control of LED current. The PWM functions by shorting out the LED with a parallel switch allowing high PWM dimming frequencies. Additional features include thermal shutdown, VCC under-voltage lockout, and logic level shutdown mode.

  • Operating input voltage range of -9 V to -14 V w.r.t. LED anode
  • Control inputs are referenced to the LED anode
  • Output current greater than 6 A
  • Greater than 30 kHz PWM frequency capable
  • Negative output voltage capability allows LED anode to be tied directly to chassis for maximum heat sink efficiency
  • Two control inputs are used to modulate LED brightness
  • No output capacitor required
  • Up to 1 MHz switching frequency
  • Low IQ, 1 mA typical
  • Soft start
  • Adaptive programmable ON time allows for constant ripple current
  • LLP-24 package
  • LCD backlighting
  • Projection systems
  • Solid state lighting
  • Automotive lighting

LED Driver

ImageManufacturer Part NumberDescriptionTypeTopologyAvailable QuantityView Details
LM3433SQ/NOPB datasheet linkIC LED DRIVER CTRLR DIM 24WQFNLM3433SQ/NOPBIC LED DRIVER CTRLR DIM 24WQFNDC DC ControllerStep-Down (Buck)18 - Immediate
LM3433SQ/NOPB product page link
Published: 2009-09-08