DATASHEET
ISL91110IR
High Efficiency Buck-Boost Regulator with 5.4A Switches
FN8709
Rev 0.00
April 17, 2015
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.
Features
• Accepts input voltages above or below regulated output
voltage
• Automatic and seamless transitions between buck and
boost modes
The ISL91110IR is capable of delivering at least 2A continuous
output current (V
= 3.3V) over a battery voltage range of 2.5V
• Input voltage range: 1.8V to 5.5V
OUT
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.
• Output current: up to 2A (PVIN = 3.4V, V
• Output current: up to 2A (PVIN = 2.5V, V
= 5V)
OUT
= 3.3V)
OUT
• Burst current: up to 3A (PVIN = 2.9V, V
600µs, t = 4.6ms)
= 3.3V, t <
ON
OUT
• High efficiency: up to 95%
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.
• 35µA quiescent current maximizes light load efficiency
• 2.5MHz switching frequency minimizes external component
size
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.
• Fully protected for short-circuit, over-temperature and
undervoltage
• Small 4mmx4mm 20 Ld TQFN package
The ISL91110IR is available in a 4mmx4mm, 20 Ld TQFN
package.
Applications
• Smartphones and tablet PCs
TABLE 1. KEY DIFFERENCES BETWEEN FAMILY OF PARTS
• Wireless communication devices
• Optical modules networking equipment
PART NUMBER
ISL91110IRNZ-T
ADJ or FIXED V
OUT
3.3
3.3
3.5
3.5
ADJ
ADJ
ISL91110IRNZ-T7A
ISL91110IR2AZ-T
ISL91110IR2AZ-T7A
ISL91110IRAZ-T
Related Literature
UG022, “ISL91110IRx-EVZ Evaluation Boards User Guide”
ISL91110IRAZ-T7A
100
ISL91110IRNZ
VIN
=
V
= 4.2V
IN
1.8V TO 5.5V
95
90
85
80
75
70
PVIN
LX1
LX2
L1
1µH
C1
2x10µF
VOUT = 3.3V
UP TO 3A
VIN
EN
VOUT
C2
2x22µF
V
= 3.6V
IN
MODE
FB
V
= 3.3V
IN
V
= 3V
1000
IN
1
10
100
LOAD CURRENT (mA)
FIGURE 2. EFFICIENCY: V
OUT
= 3.3V, T = +25°C
A
FIGURE 1. TYPICAL APPLICATION: V
OUT
= 3.3V
FN8709 Rev 0.00
April 17, 2015
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