The ISL91134 is an integrated boost switching regulator for battery-powered applications. The device provides a power supply solution for products using a one-cell Li-ion or Li-polymer battery. The device is capable of delivering up to 1.8A output current from VIN = 3V and VOUT = 5V. The no load quiescent current is only 108µA in Boost Mode and 45µA in Forced Bypass Mode, which significantly reduces the standby consumption.

The ISL91134 offers a Bypass Mode operation where the output is directly connected to the input through a 38mΩMOSFET to allow a significantly lower dropout voltage. The Bypass Mode can be entered by an external command or by auto bypass. The Forced Bypass Mode allows the output voltage to operate close to the input voltage and improves the efficiency under these conditions.

The ISL91134 is designed to support a fixed output voltage of 5V. A voltage select pin is available for each output variant to scale up the output voltage by a small offset to compensate the load transient droop. The ISL91134 requires only an inductor and a few external components to operate. The 2.5MHz switching frequency further reduces the size of external components. The ISL91134 is available in a 16 bump, 0.4mm pitch, 1.78mmx1.78mm WLCSP.


  • Input voltage range: 2.35V to 5.4V
  • Output current: up to 1.8A (VIN = 3V, VOUT = 5V)
  • High efficiency: up to 96%
  • 108μA quiescent current minimizes standby consumption in Boost Mode, 45μA in Forced Bypass Mode
  • 2.5MHz switching frequency minimizes external component size
  • Forced Bypass or Auto Bypass Modes with a 38mΩ switch
  • PFM mode at light-load currents
  • Fully protected for overcurrent, over-temperature, and undervoltage
  • Load disconnect when disabled
  • Small 1.78mmx1.78mm WLCSP


  • Smartphones and tablet PCs
  • Wireless communication devices
  • 2G/3G/4G RF power amplifiers
  • USB OTG power source

tuneProduct Options

Part Number Part Status Pkg. Type Carrier Type MOQ Buy Sample
Active WLCSP-TKCURDLBC Reel 3000


Title language Type Format File Size Date
Datasheets & Errata
star ISL91134 Datasheet Datasheet PDF 687 KB
Application Notes & White Papers
Five Easy Steps to Create a Multi-Load Power Solution White Paper PDF 846 KB
AN9208: High Frequency Power Converters Application Note PDF 592 KB
AN1681: Grounding Techniques Application Note PDF 509 KB
AN1684: Nonideality of Ground Application Note PDF 397 KB

memoryBoards & Kits

Part Number Title Type Company
ISL91134IIQ-EVZ High Efficiency 1.8A Boost Regulator with Input-to-Output Bypass Evaluation Board Evaluation Renesas

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