ISL9109
®
Data Sheet
September 29, 2008
FN6681.1
RF PA 1.5A DC/DC Regulator
Features
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
• Integrated Synchronous Buck Regulator with up to 95%
Efficiency
• 2.7V to 5.5V Supply Voltage
• 1.5A Output Current
• 4.3µA Quiescent Supply Current in Standby Mode
• 22µA Quiescent Supply Current in Skip (Low I ) Mode
Q
• 3% Output Accuracy Over Temperature/Load/Line
• Selectable Forced PWM Mode or Skip Mode
• Less Than 1µA Logic Controlled Shutdown Current
• 100% Maximum Duty Cycle for Lowest Dropout
• Soft-Start
mode selection of forced PWM mode and Skip (Low I )
Q
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.
• Peak Current Limiting, Short Circuit Protection
• Over-Temperature Protection
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.
• 8 Ld 2mmx3mm DFN
• Pb-Free (RoHS Compliant)
The ISL9109 is offered in 8 Ld 2mmx3mm DFN package
with 0.9mm typical height. The complete converter can
occupy less than 1cm area.
Applications
2
• Single Li-Ion Battery-Powered Equipment
• RF Power Amplifier
Ordering Information
• CPU Power
PART
NUMBER
(Note)
TEMP.
RANGE
(°C)
PART
MARKING
PACKAGE
(Pb-free)
PKG.
DWG. #
• PDAs and Palmtops
Pinout
ISL9109IRZ* 109
-40 to +85 8 Ld 2x3 DFN
L8.2x3
ISL9109
(8 LD 2X3 DFN)
TOP VIEW
*Add “-T” suffix for tape and reel. Please refer to TB347 for details
on reel specifications.
NOTE: These Intersil Pb-free plastic packaged products employ
special Pb-free material sets, molding compounds/die attach
materials, and 100% matte tin plate plus anneal (e3 termination
finish, which is RoHS compliant and compatible with both SnPb and
Pb-free soldering operations). Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed
the Pb-free requirements of IPC/JEDEC J STD-020.
VIN
SW
1
2
3
4
8
7
6
5
EN
N/C
GND
FB
MODE
STBY
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1
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