Maxim Launches 8-String WLED Driver Accurate Dimming Control

Maxim Integrated Products has introduced its MAX17061 8-string white-LED (WLED) driver with an integrated MOSFET switch. This device utilizes an internal switch, current-mode, step-up controller to drive the LED array, which can be configured for up to eight parallel strings with ten LEDs per string. To ensure even LED brightness, each string employs a current source that achieves ±1.5% current-balance accuracy between strings. Additionally, the MAX17061 generates a DPWM signal for accurate WLED dimming control. The DPWM's signal is controlled through a PWM interface, an SMBus-compatible interface, or both. To further enhance flexibility, the DPWM signal's frequency is set by an external resistor. The accuracy and versatility of this control scheme make the MAX17061 ideal for WLED backlighting in notebook applications.



This device features low feedback voltage at each LED string (625mV at 25mA LED current) to reduce power loss and improve efficiency. A selectable switching frequency (500kHz, 750kHz, or 1MHz) allows designers to optimize efficiency relative to component size for their applications. A robust device, the MAX17061 has multiple protection features, including output-overvoltage, open-string, short-string, and thermal-shutdown protection. The MAX17061 operates from a wide, 4.5V to 26V input-voltage range, and provides a fixed (25mA) or adjustable (15mA to 30mA) full-scale LED current. Available in a small, 4mm x 4mm, 28-pin TQFN package, the MAX17061 is fully specified over the -40 degrees Celsius to +85 degrees Celsius extended temperature range. Prices start at $2.59 (1000-up, FOB USA). An evaluation kit is available to reduce design time.