Highest Efficiency WLED Drivers Enable the Industry’s Smallest Solution

Highest Efficiency WLED Drivers Enable the Industry's Smallest Solution

Maxim introduced the MAX8901A/MAX8901B: high efficiency white-LED (WLED) drivers, which achieve up to 92% efficiency while driving a string of 2 to 6 WLEDs.

The MAX8901A/MAX8901B are the highest efficiency, step-up DC-DC converters to drive a string of 2 to 6 WLEDs

Designed to drive 2 to 6 WLEDs for backlighting, the MAX8901A/MAX8901B are ideal for the 1.5in to 4in LCDs used in battery-operated devices such as smartphones, PDAs, portable media players, GPS devices, and digital still cameras.

The MAX8901A/MAX8901B provide a single input to enable the IC and to control LED intensity. With the LED current proportional to the PWM duty cycle, the MAX8901A uses a direct-PWM input to regulate LED intensity. In contrast, the MAX8901B uses single-wire, serial-pulse dimming that reduces LED intensity in 32 linear steps. Full-scale LED current for serial-pulse dimming is 24.75mA, and each step is 0.75mA.

In addition to providing flexible dimming control, the MAX8901A/MAX8901B integrate robust protection features: internal soft-start to eliminate inrush currents during startup, input overvoltage protection, LED overvoltage protection, undervoltage lockout, and thermal shutdown. To conserve battery power, these WLED drivers consume only 0.1µA (typ) in shutdown mode.

The MAX8901A/MAX8901B are available in a space-saving, thermally enhanced, 2mm x 2mm, 8-pin TDFN package that is fully specified over the -40°C to +85°C extended temperature range.