The ISL8009A is a high efficiency, monolithic, synchronous step-down DC/DC regulator that can deliver up to 1.5A continuous output current. It is optimized for generating low output voltages down to 0.8V. The supply voltage range of 2.7V to 5.5V, allows the use of single Li+cell, three NiMH cells or a regulated 5V input. The ISL8009A uses current mode control architecture to deliver very low duty cycle operation at high frequency with fast transient response and excellent loop stability. It has flexible operation mode selection of forced PWM mode and automatic PFM/PWM with as low as 17A quiescent current, achieving high power conversion efficiency under light load condition, hence maximizing battery life. High 1.6MHz pulse-width modulation (PWM) switching frequency allows the use of small external components.