700mA Step-Down Converters Provide Flexible Control in a Tiny CSP

The individual logic on/off controls for each output allow the user full control over output sequencing. To further enhance flexibility, the MAX8884Y/MAX8884Z have individual enables for the step-down converter and two LDO outputs, as well as pin-selectable output voltages for the step-down converter (1.2V/1.8V) and one LDO (1.8V/2.8V). Combining flexible control with high efficiency (> 90%) and a compact footprint, the MAX8884Y/MAX8884Z are well 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 2.7V, generate only 26microVrms (typ) output noise, and have a 65dB (typ) PSRR. The step-down converter guarantees 700mA output current with low output-voltage ripple ranging from 15mVp-p to 20mVp-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 degrees Celsius to +85 degrees Celsius extended temperature range. The MAX8884Y/MAX8884Z are available in a lead-free, 2mm x 2mm x 0.7mm, 16-bump CSP. Prices start at $1.45 (2500-up, FOB USA).