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MAX16834 High-Power LED Driver


Maxim’s LED driver for boost, boost-buck, SEPIC, and high-side buck topologies


MAX16834 High-Power LED DriverMaxim's MAX16834 is a current-mode, high-brightness LED (HB LED) driver for boost, boost-buck, SEPIC, and high-side buck topologies. In addition to driving an n-channel power MOSFET switch controlled by the switching controller, it also drives an n-channel PWM dimming switch to achieve LED PWM dimming. This LED driver integrates all the building blocks necessary to implement a fixed-frequency HB LED driver with wide-range dimming control. The MAX16834 features constant-frequency peak current-mode control with programmable slope compensation to control the duty cycle of the PWM controller.

A dimming driver designed to drive an external n-channel MOSFET in series with the LED string provides wide-range dimming control up to 20kHz. In addition to PWM dimming, the MAX16834 provides analog dimming using a DC input at REFI. The programmable switching frequency (100kHz to 1MHz) allows design optimization for efficiency and board space reduction. A single resistor from RT/SYNC to ground sets the switching frequency from 100kHz to 1MHz, while an external clock signal at RT/SYNC disables the internal oscillator and allows the MAX16834 to synchronize to an external clock. The device’s integrated high-side current-sense amplifier eliminates the need for a separate high-side LED current-sense amplifier in boost-buck applications.

The MAX16834 operates over a wide supply range of 4.75V to 28V and includes a 3A sink/source gate driver for driving a power MOSFET in high-power LED driver applications. It can also operate at input voltages greater than 28V in boost configuration with an external voltage clamp. This driver is also suitable for DC-DC converter applications such as boost or buck-boost. Additional features include external enable/disable input, an on-chip oscillator, fault indicator output (active-low FLT) for LED open/short or over-temperature conditions, and an overvoltage protection sense input (OVP+) for true overvoltage protection.

The MAX16834 is available in a thermally enhanced 4mm x 4mm, 20-pin TQFN-EP package and in a thermally enhanced 20-pin TSSOP-EP package and is specified over the automotive -40°C to +125°C temperature range.

Features

  • Wide input operating voltage range (4.75V to 28V)
  • Works for input voltage > 28V with external voltage clamp on VIN for boost converter
  • 3000:1 PWM dimming/analog dimming
  • Integrated PWM dimming MOSFET driver
  • Integrated high-side current-sense amplifier for LED current sense in boost-buck converter
  • 100kHz to 1MHz programmable high-frequency operation
  • External clock synchronization input
  • Programmable UVLO
  • Internal 7V low-dropout regulator
  • Fault output (active-low FLT) for overvoltage, overcurrent, and thermal warning faults
  • Programmable true differential overvoltage protection
  • 20-pin TQFN-EP and TSSOP-EP packages

Applications

  • Architectural and decorative lighting (MR16, MR111)
  • Automotive rear and front lighting
  • DC-DC boost/boost-buck converters
  • Projection system RGB LED light sources
  • Single-string LED LCD backlighting
  • Spot and ambient lights

Digi-Key P/N Manufacturer P/N Package Description Datasheet
MAX16834ATP+-ND MAX16834ATP+ 20-TQFN-EP IC LED DRIVR HIGH BRIGHT 20-TQFN Datasheet