ISL9105 is a 600mA, 1.6MHz step-down regulator that isideal for powering low-voltage microprocessors in handhelddevices such as PDAs and cellular phones. It is optimizedfor generating low output voltages down to 0.8V. The supplyvoltage range is from 2.7V to 5.5V, allowing for the use of asingle Li+ cell, three NiMH cells or a regulated 5V input. Ithas a guaranteed minimum output current of 600mA.1.6MHz pulse-width modulation (PWM) switching frequencyallows for use of small external components. It has flexibleoperation mode selection of forced PWM mode and low IQmode with typical 25μA quiescent current for highest lightload efficiency to maximize battery life.The ISL9105 includes a pair of low ON-resistanceP-Channel and N-Channel internal MOSFETs to maximizeefficiency and minimize external component count. 100%duty-cycle operation allows less than 200mV dropout voltageat 600mA output current.The ISL9105 offers a typical 216ms Power-On-Reset (POR)timer at power-up. The timer output can be reset by RSI.When shutdown, ISL9105 discharges the output capacitor.Other features include internal digital soft-start, enable forpower sequence, overcurrent protection, and thermalshutdown.The ISL9105 is offered in a 2mmx3mm 8 Ld DFN packagewith 1mm maximum height. The complete converteroccupies less than 1cm2 area.