ISL91127IR Datasheet, PDF (1/12 Pages) Intersil Corporation – High Efficiency Buck-Boost Regulator with 4.5A Switches

DATASHEET
High Efficiency Buck-Boost Regulator with 4.5A
Switches
ISL91127IR
The ISL91127IR 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 ISL91127IR 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 30µA optimize efficiency under all load
conditions.
The ISL91127IR 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 1.0V or as
high as 5.2V are supported.
The ISL91127IR is available in a 20 Ld, 0.5mm pitch QFN
(4mmx4mm) package. The 2.5MHz switching frequency further
reduces the size of external components.
Related Literature
• UG080, “ISL91127IRN-EVZ, ISL91127IR2A-EVZ,
ISL91127IRA-EVZ Evaluation Boards User Guide”
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 = 2.5V, V_OUT = 3.3V)
• High efficiency: up to 96%
• 30µA quiescent current maximizes light-load efficiency
• 2.5MHz switching frequency minimizes external component
size
• Fully protected for short-circuit, over-temperature and
undervoltage
• 20 Ld 4mmx4mm QFN package
Applications
• Handheld and battery powered consumer and medical devices
• Brownout free system voltage for smartphones and tablet PCs
• Wireless communication devices
• 2G/3G/4G RF power amplifiers
V_{IN =} 1.8V TO 5.5V
C₁
10µF
ISL91127IRNZ
PVIN
LX1
VIN
EN
MODE
LX2
VOUT
FB
SGND PGND
L₁
1µH
V_OUT = 3.3V
C₂
2x22µF
FIGURE 1. TYPICAL APPLICATION: V_OUT = 3.3V
100
95
90
85
VIN = 2.5V
80
VIN = 3.3V
75
70
1
VIN = 3.6V
VIN = 4V
10
100
LOAD CURRENT (mA)
1000
FIGURE 2. EFFICIENCY: V_OUT = 3.3V, T_A = +25°C
August 3, 2016
1
FN8859.1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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