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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

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1.2A High Efficiency Buck-Boost Regulators

ISL9110, ISL9112

The ISL9110 and ISL9112 are highly-integrated Buck-Boost

switching regulators that accept input voltages either above or

below the regulated output voltage. Unlike other Buck-Boost

regulators, these regulators automatically transition between

operating modes without significant output disturbance.

Both parts are capable of delivering up to 1.2A output current,

and provide excellent efficiency due to their fully synchronous

4-switch architecture. No-load quiescent current of only 35µA

also optimizes efficiency under light-load conditions. Forced

PWM and/or synchronization to an external clock may also be

selected for noise sensitive applications.

The ISL9110 is designed for standalone applications and

supports 3.3V and 5V fixed output voltages or variable output

voltages with an external resistor divider. Output voltages as low

as 1V, or as high as 5.2V are supported using an external resistor

divider.

The ISL9112 supports a broader set of programmable features

programmable output voltage range of 1.9V to 5V, the ISL9112

is ideal for applications requiring dynamically changing supply

voltages. A programmable slew rate can be selected to provide

smooth transitions between output voltage settings.

The ISL9110 and ISL9112 require only a single inductor and very

few external components. Power supply solution size is

minimized by a tiny 3mmx3mm package and a 2.5MHz

switching frequency, which further reduces the size of external

components.

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 1.2A

• High Efficiency: Up to 95%

• 35µA Quiescent Current Maximizes Light-load Efficiency

• 2.5MHz Switching Frequency Minimizes External Component

Size

• Selectable Forced-PWM Mode and External Synchronization

• Fully Protected for Overcurrent, Over-temperature and

Undervoltage

• Small 3mmx3mm TDFN Package

Applications

• Regulated 3.3V from a Single Li-Ion Battery

• Smart Phones and Tablet Computers

• Handheld Devices

•Point-of-Load Regulators

Related Literature

• See AN1648 “ISL9110IRTNEVAL1Z, ISL9110IRT7EVAL1Z,

ISL9110IRTAEVAL1Z Evaluation Board User Guide”

• See AN1647 “ISL9112IRTNEVAL1Z, ISL9112IRT7EVAL1Z

EvaluationBoard User Guide”

FIGURE 1. TYPICAL APPLICATION

3.3V/1A

VOUT 1

FB 12

C2

10µF

BAT

PG

STATUS

OUTPUTS

8

7

PVIN

1.8V TO 5.5V

VIN

5

6

MODE

EN

10

9

C1

10µF

ISL9110IRTNZ

LX1

LX2

4

2

L1

2.2µH

70

75

80

85

90

95

100

0.01

0.05

0.25

1.25

FIGURE 2. EFFICIENCY

July 13, 2012

FN7649.2