High frequency 400mA step-down converter enables smallest solution size for portable applications

Developers of mobile handsets and modules for new smart phone applications, such as Digital Media Broadcast (DMB) and Digital Video Broadcast (DVB), strive to drive down system thickness and footprint. By enabling the use of a 0603 footprint 1mm high inductor, and coming in a small, 2.0 x 2.1 mm SC70JW package, the AAT1149 delivers the power these applications need while setting new standards in solution size and power efficiency.

The AAT1149 delivers 400mA of load current from an input range of 2.7V to 5.5V. Output voltage is programmable via external feedback resistors from 1.0V to VIN. The step-down converter achieves up to a high 98 percent efficiency.

No load quiescent current is only 45µA. The 3MHz switching frequency allows the use of extremely 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 70µs soft start feature limits current surge and eliminates output voltage overshoot at startup.

Specified over the -40 to +85 degrees C temperature range, the AAT1149 is available in a Pb-free, 8-pin SC70JW package that measures only 2.0 x 2.1mm.