Advanced Analogic Technologies’ AAT1149 is a high-performance, 400-mA stepdown converter. Developed for space-constrained portable applications, the fast transient converter enables the use of the 0603 footprint, 1-mm high inductors for the smallest possible total solution size.
The AAT1149 delivers 400 mA of load current from an input range of 2.7 V to 5.5 V. Output voltage is programmable via external feedback resistors from 1.0 V to VIN. The stepdown converter achieves up to 98% efficiency. No-load quiescent current is only 45 µA. The 3-MHz switching frequency allows the use of small external components and keeps switching losses low.
To prevent damage during overload conditions, the AAT1149 adds current limit protection. An over temperature protection circuit disables switching if internal dissipation becomes excessive. An integrated 70-µs Soft Start feature limits current surge and eliminates output voltage overshoot at startup.
The AAT1149 is available in an 8-pin SC70JW package that measures only 2.0 mm x 2.1 mm. It sells for $0.87 each in 1000 piece quantities.