MAX16807

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.

Features of the MAX16807 are:(1)eight constant-current output channels (up to 55mA each); (2)paralleling channels allows higher current per LED string; (3)output rated for 36V continuous voltage; (4)output-enable pin for PWM dimming (up to 30kHz); (5)one resistor sets LED current for all channels; (6)wide dimming ratio up to 5000:1; (7)low current-sense reference (300mV) for high efficiency; (8)8V to 26.5V input voltage or higher with external biasing devices; (9)4-wire serial interface to control individual output channels.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.

The absolute maximum ratings of the MAX16807 can be summarized as:(1)VCC to AGND:-0.3V to +30V;(2)storage temperature range:-65 to +150;(3)operating temperature range:-40 to +125;(4)junction temperature:+150;(5)V+ to PGND:-0.3V to +6V;(6)total PGND current:480mA.Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied.Exposure to absolute maximum rating conditions for extended periods may affect device reliability.The advantages of current-mode control over voltagemode control are twofold. First, there is the feed-forward characteristic brought on by the controller's ability to adjust for variations in the input voltage on a cycleby-cycle basis. Second, the stability requirements of the current-mode controller are reduced to that of a single pole system unlike the double pole in the voltagemode control scheme.