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

Status

Active: In Production.

Description

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The MAX16834 is a current-mode high-brightness LED (HB LED) driver for boost, buck-boost, 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 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 MAX16834's integrated high-side current-sense amplifier eliminates the need for a separate high-side LED current-sense amplifier in buck-boost 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. 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 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.

An evaluation kit is available: MAX16834EVKIT

Key Features		Applications/Uses
Wide Input Operating Voltage Range (4.75V to 28V) Works for Input Voltage > 28V with External Voltage Clamp on V_IN 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 Buck-Boost 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 Packages		Architectural and Decorative Lighting (MR16, MR111) Automotive Rear and Front Lighting DC-DC Boost/Buck-Boost Converters Projection System RGB LED Light Sources Single-String LED LCD Backlighting Spot and Ambient Lights

Key Specifications: High Brightness LED Drivers

Part Number

Topology

V_IN
(V)

Extended V_IN with External Bias

LED Channels

I_LED per Channel
(A)

LED String Volt.

Internal Pwr. MOSFETs

Freq.

PWM Dimming Freq.
(kHz)

PWM Dimming Ratio

EV Kit

Price

min

max

See Notes

MAX16834

Boost

Buck

Buck-Boost

Inductor Based

4.75

Yes

Set externally

100kHz to 1MHz

1:3000

Yes

$1.24 @1k

See All High Brightness LED Drivers (26)

Key Specifications: White LED Drivers

Part Number

Topology

LEDs

Config.

Dimming Control

V_{CURR_SENSE}
(mV)

P_OUT
(W)

I_LED
(mA)

V_IN
(V)

I_CC
(mA)

V_OUT
(V)

Oper. Freq.
(kHz)

Package/Pins

Price

max num. of

max

min

max

See Notes

MAX16834

Boost

Buck

Buck-Boost

Inductor Based

100

Series

Series-Parallel

Analog

PWM

200

1500

4.75

100

1000

TQFN/20

TSSOP-EP/20

$1.24 @1k

See All White LED Drivers (47)

Diagram

Typical Operating Circuit

source��ShenZhen henlito electronic co.,ltd.

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