Maxim Releases Negative-Charge-Pump White-LED Driver With Two LDO Regulators
Maxim Integrated Products introduced the MAX8822, which it describes as the industry’s only white-LED (WLED) driver to combine a highly efficient negative charge pump with two independent, low-dropout (LDO) regulators.
Available in a 3 x 3 x 0.8mm TQFN package, this single-chip solution for driving up to four WLEDs is said to be 50% smaller than the standard two-chip solution. 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 utilizes independent, adaptive-mode switching for each LED to further extend battery life, even with large LED forward-voltage (VF) mismatch. It is claimed that these features enable the MAX8822 to be 12% more efficient than competing solutions, thus making it suitable for use in cell phones, smartphones, PDAs, and other handheld devices in which space and battery life are precious.
The LDO regulators provide a low 45µVrms 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 to +85° extended temperature range.
Prices start at $1.55 (2500-up, FOB USA). An evaluation kit is available to speed designs.
