Buck converter boosts modem efficiency

The device combines two PWM step down DC/DC converters in a 2.5 x 2mm package. Its pulse skipping mode enables a reduction in quiescent current under light load operation, helping to maximise portable device battery life. Further power savings are achieved by the converters' 100% duty cycle, which allows systems to operate at the lowest voltage supply. With an input voltage range from 2.7 to 5.5V, the 17pad converters support the use of single Li+/Li polymer cells, multiple alkaline/NiMH cells, USB power supplies and many other standard power sources. The device offers a 1A, 1.8V fixed voltage output and a 2A, adjustable (0.9V to VIN) voltage output, each with an independent active high channel enable pin. In addition, it integrates an internal power switch and synchronous rectifier on each output, and offers a high operating frequency of 1.2MHz.