DATASHEET
ISL91110
FN8434
Rev 4.00
February 5, 2016
High Efficiency Buck-Boost Regulator with 4.5A Switches
The ISL91110 is a high-current buck-boost switching regulator
for systems using new battery chemistries. It uses Intersil’s
proprietary buck-boost algorithm to maintain voltage
regulation while providing excellent efficiency and very low
output voltage ripple when the input voltage is close to the
output voltage.
Features
• Accepts input voltages above or below regulated output
voltage
• Automatic and seamless transitions between buck and
boost modes
The ISL91110 is capable of delivering at least 2A continuous
• Input voltage range: 1.8V to 5.5V
output current (V
= 3.3V) over a battery voltage range of
OUT
• Output current: up to 2A (PVIN = 2.5V, V
OUT
= 3.3V)
2.5V to 4.35V. This maximizes the energy utilization of
advanced single-cell Li-ion battery chemistries that have
significant capacity left at voltages below the system voltage.
Its fully synchronous low ON-resistance 4-switch architecture
and a low quiescent current of only 35µA optimize efficiency
under all load conditions.
• Burst current: up to 3A (PVIN = 3V, V
600µs, t = 4.6ms)
= 3.3V, t <
ON
OUT
• High efficiency: up to 96%
• 35µA quiescent current maximizes light-load efficiency
• 2.5MHz switching frequency minimizes external component
size
The ISL91110 supports standalone applications with a fixed
3.3V or 3.5V output voltage or adjustable output voltage with
an external resistor divider. Output voltages as low as 1.0V or
as high as 5.2V are supported.
• Fully protected for short-circuit, over-temperature, and
undervoltage
• Small 2.33mmx2.07mm WLCSP
The ISL91110 is available in a 25-bump, 0.4mm pitch WLCSP
(2.33mmx2.07mm) and a 2.5MHz switching frequency, which
further reduces the size of external components.
Applications
• Brownout free system voltage for smartphones and tablet
PCs
• Wireless communication devices
• 2G/3G/4G RF power amplifiers
Related Literature
• AN1912 “ISL91110IIN-EVZ, ISL91110II2A-EVZ,
ISL91110IIA-EVZ Evaluation Boards”
100
V
= 4.0V
IN
ISL91110IINZ
V
1.8V TO 5.5V
IN =
LX1
95
90
85
80
75
PVIN
C
1
L
1
1µH
2x10µF
VOUT = 3.3V
LX2
VIN
EN
IOUT = UP TO 3A
V
= 3.6V
IN
VOUT
V
= 3.3V
IN
C
2
V
= 3.0V
IN
2x22µF
FB
MODE
V
= 2.5V
IN
NOTE: Confirm with Intersil Applications Engineer for any deviation
from a bove circ uit
1
10
100
LOAD CURRENT (mA)
1000
FIGURE 1. TYPICAL APPLICATION: V
OUT
= 3.3V
FIGURE 2. EFFICIENCY: V
OUT
= 3.3V, T = +25°C
A
FN8434 Rev 4.00
February 5, 2016
Page 1 of 12