Maxim Integrated Products introduces the MAX17127, a six-string WLED driver that provides a complete backlighting solution for notebooks and netbooks. The step-up controller integrates a 48V MOSFET capable of driving up to 13 LEDs/string. The controller frequency can be programmed from 250kHz to 1MHz, allowing flexibility in selecting external components.

The MAX17127 features a input-voltage range of 5V to 26V, making it well suited for both netbooks that use a 2- to 3-cell Li+ battery and notebooks that use a larger battery. The current in each string can be programmed from 10mA to 30mA using an external resistor, which helps in setting the appropriate brightness level. Meanwhile, better than ±2% accurate current matching between strings ensures even LED brightness. The device operates in a direct-dimming mode with a dimming frequency ranging from 100Hz to 25kHz.

The LED current is directly controlled by the external dimming signal's frequency and duty cycle. The wide dimming range eliminates the audible noise issues usually encountered in WLED drivers. A low feedback voltage at each LED string helps reduce power loss and improve efficiency. The chip offers multiple features to protect the controller from faults, including overcurrent, overtemperature, and open-/short-string conditions.

Additionally, the step-up controller has cycle-by-cycle current limiting and soft-start capability to control inrush current. The MAX17127 is available in a 4mm x 4mm, 20-pin TQFN package and operates over the -40°C to +85°C extended temperature range. Prices start at $0.73 (1000-up, FOB USA).