1
DATASHEET
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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High Efficiency Buck-Boost Regulator with 5.4A
Switches
ISL91110IR
The ISL91110IR 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.
The ISL91110IR is capable of delivering at least 2A continuous
output current (V
OUT
= 3.3V) over a battery voltage range of 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.
The ISL91110IR 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 1V or as high as 5.2V are
supported.
The ISL91110IR requires only a single inductor and very few
external components. Power supply solution size is minimized by its
2.5MHz switching frequency, allowing small size external
components.
The ISL91110IR is available in a 4mmx4mm, 20 Ld TQFN package.
Features
• Accepts input voltages above or below regulated output
voltage
• Automatic and seamless transitions between buck and boost
modes
• Input voltage range: 1.8V to 5.5V
• Output current: up to 2A (PVIN = 3.4V, V
OUT
= 5V)
• Output current: up to 2A (PVIN = 2.5V, V
OUT
= 3.3V)
• Burst current: up to 3A (PVIN = 2.9V, V
OUT
= 3.3V, t
ON
< 600µs,
t = 4.6ms)
• High efficiency: up to 95%
• 35µA quiescent current maximizes light load efficiency
• 2.5MHz switching frequency minimizes external component
size
• Fully protected for short-circuit, over-temperature and
undervoltage
• Small 4mmx4mm 20 Ld TQFN package
Applications
• Smartphones and tablet PCs
• Wireless communication devices
• Optical modules networking equipment
Related Literature
UG022, “ISL91110IRx-EVZ Evaluation Boards User Guide”
TABLE 1. KEY DIFFERENCES BETWEEN FAMILY OF PARTS
PART NUMBER ADJ or FIXED V
OUT
ISL91110IRNZ-T 3.3
ISL91110IRNZ-T7A 3.3
ISL91110IR2AZ-T 3.5
ISL91110IR2AZ-T7A 3.5
ISL91110IRAZ-T ADJ
ISL91110IRAZ-T7A ADJ
FIGURE 1. TYPICAL APPLICATION: V
OUT
= 3.3V
FIGURE 2. EFFICIENCY: V
OUT
= 3.3V, T
A
= +25°C
PVIN
V
IN
=
1.8V TO 5.5V
V
OUT
= 3.3V
UP TO 3A
ISL91110IRNZ
VIN
EN
LX1
LX2
VOUT
FB
SGND
PGND
C
1
2x10µF
L
1
1µH
C
2
2x22µF
MODE
70
75
80
85
90
95
100
1 10 100 1000
V
IN
= 3.6V
V
IN
= 3V
V
IN
= 4.2V
V
IN
= 3.3V
EFFICIENCY (%)
LOAD CURRENT (mA)
April 17, 2015
FN8709.0
