MAX17149

EVALUATION KIT AVAILABLE MAX17129/MAX17149 Low-Cost, 6-String WLED Drivers with Quick-PWM Step-Up Converter General Description The MAX17129/MAX17149 are high-efficiency drivers for white LEDs. They are designed for small- to mediumsized LCDs that employ an array of LEDs as the light source. An internal switch step-up controller with QuickPWM™ drives the LED array, which can be configured for up to 6 strings in parallel and either 11 LEDs (MAX17129) or 6 LEDs in series (MAX17149) per string. Each string is terminated with a ballast that achieves ±2% currentregulation accuracy, ensuring even LED brightness and provides an adjustable 10mA to 45mA full-scale LED current. The devices have a wide input voltage range of 6V to 26V. The MAX17129 integrates an LDO to simplify applications that have a single high-voltage supply. The devices also feature a low-input-voltage mode for applications that have a 3V to 5.5V supply voltage. The devices support both PWM and hybrid dimming mode. In PWM dimming mode, the external PWM signal directly controls the brightness of LEDs. The dimming frequency ranges from 100Hz to 25kHz with 400ns minimum on-time. In hybrid dimming mode, the LED current amplitude can be adjusted to 25% of full-scale LED current to improve system efficiency when brightness is low. The devices have multiple features to protect the controller from fault conditions. Separate voltagefeedback loops limit the output voltage to safe operation. The open- and short-LED detecti...