ISL9109 pdf datasheet (RF PA 1

RF PA 1.5A DC/DC Regulator
ISL9109 is 1.6MHz synchronous step-down regulator with
integrated power switches capable of delivering 1.5A output
for powering RF Power Amplifiers in cellular phones. The
ISL9109 features a standby mode which allows for rapid
startup while prolonging battery life. The supply voltage
range is from 2.7V to 5.5V allowing the use of a single Li+
cell, three NiMH cells, or a regulated 5V input. 1.6MHz
pulse-width modulation (PWM) switching frequency allows
using small external components. It has a flexible operation
mode selection of forced PWM mode and Skip (Low IQ)
mode with typical 22μA quiescent current for highest light
load efficiency to maximize battery life.
The ISL9109 integrates a pair of low ON-resistance
P-Channel and N-Channel MOSFETs to maximize efficiency
and minimize external component count.
When in standby, the ISL9109 band-gap reference is
powered. This assists in a rapid power-up when the EN pin
is asserted high. Other features include soft-start,
overcurrent protection, and thermal shutdown.
The ISL9109 is offered in 8 Ld 2mmx3mm DFN package
with 0.9mm typical height. The complete converter can
occupy less than 1cm2 area.