Programmable, Four-String HB LED Driver With Output-Voltage Optimization And Fault Detection

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 cur- rent 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 config- urable 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 chan- nel 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 volt- age 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. By Maxim Integrated Products