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 17μA 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.
The ISL8009A integrates a pair of low ON-resistance
P-Channel and N-Channel internal MOSFETs to maximize
efficiency and minimize external component count. The
100% duty-cycle operation allows less than 400mV dropout
voltage at 1.5A output current.
The ISL8009A offers a 2ms Power-On-Reset (POR) timer at
power-up. The timer output can be reset by RSI. When
shutdown, ISL8009A discharges the output capacitor
through a 100Ω resistor. Other features include internal
digital soft-start, enable for power sequence, overcurrent
protection, and thermal shutdown.
The ISL8009A is offered in a 2mmx3mm 8 Ld DFN package
with 1mm maximum height. The complete converter
occupies less than 1cm2 area.