Dual buck converter fuses high, low current power functions

The AAT2789 from Advanced Analogic Technologies Inc. (AnalogicTech) is a new dual buck converter for mobile consumer and wireless applications. Integrating both a high current 1.7A buck converter with a low current 800mA buck converter, the device consolidates power management functions for a wide variety of WLAN products, GPS devices, smart phones, portable media players and other handheld devices.

Operating from 2.7V to 5.5V input range, the AAT2789 2-channel synchronous step-down converter is designed for portable systems powered from a single-cell Li-ion battery or consumer equipment using a 3.3V or 5V bus. The dual converter features one channel which delivers up to 1.7A and a second channel which supplies up to 800mA. Both converter channels use a unique low noise architecture developed by AnalogicTech to minimize output ripple and spectral noise. Each converter also uses its own independent enable pin. Output voltage is externally adjustable.

Low RDS(on) power switches help improve power efficiency at high current levels. To further extend battery life, the device adds a low quiescent current, light load operating mode which maximizes power efficiency over the entire load range.

The AAT2789 also features a high switching frequency which helps minimize external filter size. Peak current mode control eliminates the need for external compensation while optimizing transient performance and stability. To ensure the integrity of the device, the AAT2789 features integrated soft start to limit inrush current. For overload conditions, the device adds over-temperature and current limit protection circuits.

Qualified across the -40°C to +85°C temperature range, the AAT2789 is available in a 3mm x 4mm, Pb-free, 16-pin TDFN package. The PMIC sells for $1.79 in 1,000 quantities.