ISL91128

High Efficiency Buck-Boost Regulator with 4.5A Switches and I2C Interface

Product Status: Mass Production

OVERVIEW

The ISL91128 is a high-current, buck-boost switching regulator for systems using new battery chemistries. It uses the Renesas 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 device also includes a selectable Bypass mode for low power consumption in applications that have a Sleep or Low Power mode.

The ISL91128 is capable of delivering at least 2.2A continuous output current (VOUT = 3.3V) across 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 ISL91128 supports a broader set of programmable features that can be accessed using an I2 C bus interface. With a programmable output voltage range of 1.9V to 5.0V, the ISL91128 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 ISL91128 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.

KEY FEATURES

  • Accepts input voltages above or below regulated output voltage
  • Automatic and seamless transitions between Buck and Boost modes
  • I2C interface
  • Input voltage range: 1.8V to 5.5V
  • Continuous output current: up to 2.4A (PVIN = 2.5V, VOUT = 3.3V)
  • High efficiency: up to 96%
  • 30µA quiescent current maximizes light-load efficiency
  • Selectable bypass power saving mode operation
  • 2.5MHz switching frequency minimizes external component size
  • Fully protected for short-circuit, over-temperature, and undervoltage
  • Small 2.15mmx1.74mm WLCSP

BLOCK DIAGRAM

 Block Diagram

PARAMETRICS

Parameters
ISL91128
Basic Information
Production Status
Mass Production
Topology
Buck-Boost
# of Outputs
1
Input Voltage Min (V)
1.8
Input Voltage Max (V)
5.5
Output Voltage Min (V)
1.9
Output Voltage Max (V)
5
Output Current Max (A)
2.4
IQ
30 µA
Switching Freq. (max) (MHz)
2.9
Switching Freq. (min) (MHz)
2.1
Max Duty Cycle (%)
-
Qualification Level
Standard
Peak Efficiency (%)
96
POR
Yes
SYNCH Capability
No
Switching Frequency Range (MHz)
2.5
Can Sample
YES
Temperature Range
-40 to +85

Design Resources and Tools

Selection Tool

 PowerCompass Online Tool

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Design

Design Tool

 PowerNavigator Software

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Simulation Tool

iSim Online Designer

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Cross Reference

Intersil Cross Reference

Cross-reference based on data from industry sources. Support for the online tool has been discontinued, but the data is still available.

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Knowledge Base

Switching Regulators FAQs

Find answers to common questions, support articles and development hints.


FAQs

Related Boards and Kits

Related Videos

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9:50
This webinar introduces three buck-boost regulators in QFN packages, ISL91127IR, ISL91107IR, ISL9120IR, for battery-powered portable devices.
3:57
This webinar introduces the ISL85003 and ISL85003A synchronous buck (step-down) regulators with integrated high-side and low-side FETs.
11:01
This webinar introduces the ISL78233, ISL78234 and ISL78235 automotive grade synchronous buck regulators for point-of-load applications.
3:02
Find out how the highly efficient, compact 12V synchronous buck regulator family can meet your power requirements for 12V rails.
9:50
This webinar introduces three buck-boost regulators in QFN packages, ISL91127IR, ISL91107IR, ISL9120IR, for battery-powered portable devices.
3:57
This webinar introduces the ISL85003 and ISL85003A synchronous buck (step-down) regulators with integrated high-side and low-side FETs.
11:01
This webinar introduces the ISL78233, ISL78234 and ISL78235 automotive grade synchronous buck regulators for point-of-load applications.
3:02
Find out how the highly efficient, compact 12V synchronous buck regulator family can meet your power requirements for 12V rails.
9:50
This webinar introduces three buck-boost regulators in QFN packages, ISL91127IR, ISL91107IR, ISL9120IR, for battery-powered portable devices.
3:57
This webinar introduces the ISL85003 and ISL85003A synchronous buck (step-down) regulators with integrated high-side and low-side FETs.
11:01
This webinar introduces the ISL78233, ISL78234 and ISL78235 automotive grade synchronous buck regulators for point-of-load applications.

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