Step-up converter shrinks handheld devices by delivering 500mA load current in TSOT23 package

As portable consumer electronic devices such as GPS receivers, cordless phones, portable instruments and portable media players, continually add features, their power needs increase.  By providing more load current than competitive products in the same footprint and supporting lower startup and operating voltages, the AAT1217 allows system designers to meet the power needs of these new functions while minimising solution size and maximising battery life.

The new device operates from a wide input voltage range of 0.5V to V_OUT.  It uses a slope compensated current mode pulse width modulation (PWM) control topology and operates at a 1.2MHz constant switching frequency.  The high switching frequency allows the use of small surface mount inductors.  An integrated synchronous rectifier eliminates the need for an external Schottky diode.

The AAT1217 switches its internal MOSFETs at high frequency to achieve efficiency levels up to 93 percent. The device also starts up at an input voltage as low as 0.85V and supports continuous operation at an input voltage down to 0.5V.

Embedded anti-ringing control circuitry minimises EMI by removing the high frequency ringing that appears on the SW pin when inductor current goes to zero. The AAT1217 also features over-current protection and a low shutdown current of < 1.0microamps.

The AAT1217 is qualified across the -40 C to +85 C temperature range.  It is available in a Pb-free, low profile 6-pin TSOT23 package.