MAX16834 High-Power LED Driver with Integrated High-Side LED Current Sense and PWM Dimming MOSFET Driver

Flexible HB LED Driver Supports Green Technology for LED Lighting, Display Backlighting, and Display Projection

Maxim's 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. The MAX16834 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 20 kHz. In addition to PWM dimming, the MAX16834 provides analog dimming using a DC input at REFI. The programmable switching frequency (100 kHz to 1 MHz) allows design optimization for efficiency and board space reduction. A single resistor from RT/SYNC to ground sets the switching frequency from 100 kHz to 1 MHz while an external clock signal at RT/SYNC disables the internal oscillator and allows the MAX16834 to synchronize to an external clock. The MAX16834'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 4.75 V to 28 V and includes a 3 A sink/source gate driver for driving a power MOSFET in high-power LED driver applications. It can also operate at input voltages greater than 28 V in boost configuration with an external voltage clamp. The MAX16834 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 overtemperature conditions, and an overvoltage protection sense input (OVP+) for true overvoltage protection.

The MAX16834 is available in a thermally enhanced 4 mm x 4 mm, 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.

Full size diagram

Key Features Applications
  • Wide Input Operating Voltage Range (4.75 V to 28 V)
  • Works for Input Voltage > 28 V 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
  • 100 kHz to 1 MHz Programmable High-Frequency Operation
  • External Clock Synchronization Input
  • Programmable UVLO
  • Internal 7 V 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
  • 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
MAX16834 High-Power LED Driver
Manufacturer Part NumberDescriptionAvailable QuantityBuy Now
8362 - Factory Stock
MAX16834EVKIT+EVAL KIT FOR MAX168341 - Immediate
54 - Factory Stock
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Published: 2015-02-04