Integrated 8-Channel LED Driver with Switch-Mode Boost and SEPIC Controller

The MAX16807 is an integrated, high-efficiency white or RGB LED driver. It is designed for LCD backlighting and other LED lighting applications with multiple strings of LEDs. The MAX16807 current-mode PWM controller regulates the necessary voltage to the LED array. Depending on the input voltage and LED voltage range, it can be used with boost or buck-boost (SEPIC) topologies. The MAX16807 features an 8V to 26.5V input voltage range. A wide range of adjustable frequency (20kHz to 1MHz) allows design optimization for efficiency and minimum board space.

The MAX16807 LED driver includes eight open-drain, constant-current-sinking LED driver outputs rated for 36V continuous operation. The LED current-control circuitry achieves ±3% current matching among strings and enables paralleling of outputs for LED string currents higher than 55mA. The output-enable pin is used for simultaneous PWM dimming of all output channels. Dimming frequency range is 50Hz to 30kHz and dimming ratio is up to 5000:1. The constant-current outputs are single resistor programmable and the LED current can be adjusted up to 55mA per output channel.

The MAX16807 operates either in stand-alone mode or with a microcontroller (µC) using an industry-standard, 4-wire serial interface.

The MAX16807 includes overtemperature protection, operates over the full -40°C to +125°C temperature range, and is available in a thermally enhanced, 28-pin TSSOP exposed paddle package.

Applications

* Ambient, Mood, and Accent Lighting * LCD White or RGB LED Backlighting: LCD TVs, Desktop and Notebook Panels, Industrial and Medical Displays

* Eight Constant-Current Output Channels (Up to 55mA Each)

* ±3% Current Matching Among Outputs

* Paralleling Channels Allows Higher Current per LED String

* Output Rated for 36V Continuous Voltage

* Output-Enable Pin for PWM Dimming (Up to 30kHz)

* One Resistor Sets LED Current for All Channels

* Wide Dimming Ratio Up to 5000:1

* Low Current-Sense Reference (300mV) for High Efficiency

* 8V to 26.5V Input Voltage or Higher with External Biasing Devices

* 4-Wire Serial Interface to Control Individual Output Channels