General Description

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.

Features

♦ 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

Applications

   LCD Backlighting:

      Automotive Infotainment Displays

      Automotive Cluster Displays

      Industrial and Desktop Monitors

      LCD TVs

   Automotive Lighting:

      Adaptive Front Lighting

      Low- and High-Beam Assemblies