MAX16826 Programmable, Four-String HB LED Driver with Output-Voltage Optimization and Fault Detection

Programmable, Four-String LED Driver with Integrated ADC Optimizes Output Voltage and Detects LED Fault Conditions

Status

Active: In Production.

Description

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The MAX16826 high-brightness LED (HB LED) driver is designed for backlighting automotive LCD displays and other display applications such as industrial or desktop monitors and LCD televisions. The MAX16826 integrates a switching regulator controller, a 4-channel linear current sink driver, an analog-to-digital converter (ADC), and an I²C interface. The IC is designed to withstand automotive load dump transients up to 40V and can operate under cold crank conditions.

The MAX16826 contains a current-mode PWM switching regulator controller that regulates the output voltage to the LED array. The switching regulator section is configurable as a boost or SEPIC converter and its switching frequency is programmable from 100kHz to 1MHz.

The MAX16826 includes 4 channels of programmable, fault-protected, constant-current sink driver controllers that are able to drive all white, RGB, or RGB plus amber LED configurations. LED dimming control for each channel is implemented by direct PWM signals for each of the four linear current sinks. An internal ADC measures the drain voltage of the external driver transistors and the output of the switching regulator. These measurements are then made available through the I²C interface to an external microcontroller (µC) to enable output voltage optimization and fault monitoring of the LEDs.

The amplitude of the LED current in each linear current-sink channel and the switch-mode regulator output voltage is programmed using the I²C interface. Additional features include: cycle-by-cycle current limit, shorted LED string protection, and overtemperature protection. The MAX16826 is available in a thermally enhanced, 5mm x 5mm, 32-pin thin QFN package and is specified over the automotive -40��C to +125��C temperature range.

MAX16826: 2008 EDN Innovation Awards Finalist (Power ICs: Drivers)

An evaluation kit is available: MAX16826EVKIT

Key Features		Applications/Uses
External MOSFETs Allow Wide-Range LED Current with Multiple LEDs per String Individual PWM Dimming Inputs per String Very Wide Dimming Range LED String Short and Open Protection Adjustable LED Current Rise/Fall Times Improve EMI Control Microcontroller Interface Using I²C Allows LED Voltage Monitoring and Optimization Using a 7-Bit Internal ADC LED Short and Open Detection Dynamic Adjustment of LED String Currents and Output Voltage Standby Mode Integrated Boost/SEPIC Controller External Switching Frequency Synchronization 4.75V to 24V Operating Voltage Range and Withstands 40V Load Dump Overvoltage and Overtemperature Protection		LCD Backlighting Automotive Infotainment Displays Automotive Cluster Displays Industrial and Desktop Monitors LCD TVs Automotive Lighting Adaptive Front Lighting Low- and High-Beam Assemblies

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

min

max

MAX16826

Boost, SEPIC + Linear

4.75

Yes

Set externally

100kHz to 1MHz

1:5000

Yes

See All High Brightness LED Drivers (26)

Diagram

Simplified Diagram

source��ShenZhen henlito electronic co.,ltd.

web:www.henlito.com