To request the full datasheet, please visit www.intersil.com/products/ISL91127
High Efficiency Buck-Boost Regulator with 4.5A Switches
The ISL91127 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
The ISL91127 is capable of delivering at least 2.1A continuous
output current (VOUT = 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 30µA optimize efficiency
under all load conditions.
The ISL91127 supports stand-alone 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 ISL91127 is available in a 20 bump, 0.4mm pitch WLCSP
(2.15mmx1.74mm) with a 2.5MHz switching frequency, which
further reduces the size of external components.
• UG045, “ISL91127IIx-EVZ Evaluation Boards User Guide”
• Accepts input voltages above or below regulated output
• Automatic and seamless transitions between buck and
• Input voltage range: 1.8V to 5.5V
• Continuous output current: up to 2.1A (PVIN = 2.5V,
VOUT = 3.3V)
• High efficiency: up to 96%
• 30µA quiescent current maximizes light-load efficiency
• 2.5MHz switching frequency minimizes external component
• Fully protected for short-circuit, over-temperature and
• Small 2.15mmx1.74mm WLCSP
• Brownout-free system voltage for smartphones and tablet
• Wireless communication devices
• 2G/3G/4G RF power amplifiers
V IN = 1.8V T O 5 .5V
IS L 911 27IIN Z
P V IN
V OUT = 3.3V
C2 x22 2 µ F
FIGURE 1. TYPICAL APPLICATION: VOUT = 3.3V
VIN = 3.6V
VIN = 4V
VIN = 3.3V
VIN = 3V
VIN = 2.5V
LOAD CURREN T (mA)
FIGURE 2. EFFICIENCY: VOUT = 3.3V
August 9, 2016
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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