Step-down converters feature 0.1-uA shutdown mode

Maxim Integrated Products introduces the MAX8884Y/MAX8884Z 700mA step-down converters with dual 300mA LDOs in a 2 x 2 mm CSP (chip-scale package). The on-board, hysteretic, PWM-controlled step-down converter provides two switching-frequency options to allow designers to optimize for highest efficiency (2 MHz) or smallest solution size (4 MHz). The individual logic on/off controls for each output allow the user full control over output sequencing.

To further enhance flexibility, the components have individual enables for the step-down converter and two LDO outputs, as well as pin-selectable output voltages for the step-down converter (1.2/1.8 V) and one LDO (1.8/2.8 V). Combining flexible control with high efficiency (> 90%) and a compact footprint, the MAX8884Y/MAX8884Z are suited for powering multiload applications in portable devices such as cell phones, smartphones, MP3 and DVD players, and digital cameras/camcorders.

These buck converter ICs integrate three discrete devices into one chip to reduce pick-and-place and inventory costs, while saving board space for other value-added features. The two low-quiescent-current LDOs operate from an input voltage as low as 2.7 V, generate only 26 microVrms (typ) output noise, and have a 65 dB (typ) PSRR. The step-down converter guarantees 700 mA output current with low output-voltage ripple ranging from 15 to 20 mVp-p. This converter also integrates a synchronous rectifier to eliminate the need for an external Schottky diode, while its high-frequency switching allows the use of tiny external components to minimize solution size.

The MAX8884Y/MAX8884Z offer a very-low-power (0.1microamps, typ) shutdown mode. Both devices feature thermal overload and overcurrent protection, and are fully specified to operate over the -40° to 85° C extended temperature range.

For more information, visit Maxim Integrated Products Inc., 120 San Gabriel Dr., Sunnyvale, CA 94086. Phone: (800) 998-8800