WLED driver packs negative charge pump, two LDOs

Maxim Integrated Products has introduced the MAX8822, said to be the industry's only white LED (WLED) driver to combine a highly efficient negative charge pump with two independent LDO regulators. Available in a 3mm x 3mm x 0.8mm TQFN package, this single-chip solution for driving up to four WLEDs is 50 percent smaller than the standard two-chip solution.

To achieve the industry's highest efficiency, the MAX8822 features a negative-charge-pump architecture that completely eliminates high-side in-line resistance, delaying 1x mode to 2x mode transition during battery discharge. It uses independent, adaptive-mode switching for each LED to further extend battery life, even with large LED forward-voltage (VF) mismatch. These innovative features enable the MAX8822 to be 12-percent more efficient than competing solutions, thus making it suitable for use in cellphones, smartphones, PDAs and other handheld devices in which space and battery life are precious.

The LDO regulators provide a low 45?Vrms noise and high 60dB PSRR output for noise-sensitive applications, such as RF, LCD panels and cameras. Output voltages are programmable in 16 different combinations using a simple, serial-pulse control interface.

The MAX8822 is fully specified over the -40°C to 85°C extended temperature range. Prices start at $1.55 (2,500-up, FOB USA). An evaluation kit is available to speed designs.