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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 the external component size
  • Fully protected from short-circuit, over-temperature, and undervoltage
  • Small 2.15mm x 1.74mm WLCSP

Description

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 I2C 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 (2.15mm x 1.74mm) with a 2.5MHz switching frequency, which further reduces the size of external components.

Parameters

AttributesValue
Topology [Rail 1]Buck-Boost
Outputs (#)1
Input Voltage (Min) [Rail 1] (V)1.8
Input Voltage (Max) [Rail 1] (V)5.5 - 5.5
Output Voltage (Min) [Rail 1] (V)1.9
Output Voltage (Max) [Rail 1] (V)5
Output Current (Max) [Rail 1] (A)3
IQ [Rail 1] (µA)30
Switching Frequency Range (Typical) (kHz)2500 - 2500
PORYes
SYNCH CapabilityNo
Peak Efficiency (%)96
Qualification LevelStandard

Package Options

Pkg. TypePkg. Dimensions (mm)Lead Count (#)Pitch (mm)
WLCSP-TKCURDL2.1 x 1.7 x 0.50200.4

Applications

  • Brownout-free system voltage for smart phones and tablet PCs
  • Wireless communication devices
  • 2G/3G/4G RF power amplifiers
Part NumberStatusSamplesStockPackageBudgetary Price (USD)Lead Count (#)Carrier TypeMoisture Sensitivity Level (MSL)Pb (Lead) FreePb Free CategoryTemp. Range (°C)Country of AssemblyCountry of Wafer Fabrication
ISL91128IINZ-T7AActiveAvailableIn StockWLCSP-TKCURDL1ku | $1.0920#Reel1YesPb-Free Ball Terminal (SAC405)-e1-40 to +85°CMALAYSIA, TAIWANTAIWAN
ISL91128IINZ-TObsoleteN/AOut of StockWLCSP-TKCURDL20#Reel1YesPb-Free Ball Terminal (SAC405)-e1-40 to +85°C

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Knowledge Base

  1. Which buck-boost regulators of the ISL91127 and ISL91128 families have an I2C interface?

    Question: Which of these buck-boost regulators have an I2C interface?   Answer: Of the products of these families, only the ISL91128 has an I2C interface. Another buck-boost regulator with I2C interface is ISL9112.

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