The ISL91127 and ISL91127IR are high-current buck-boost switching regulators for systems using new battery chemistries. They use 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.

They are capable of delivering at least 2A continuous output current (VOUT = 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. The ISL91127 and ISL91127IR have a fully synchronous low ON-resistance, 4-switch architecture and a low quiescent current of only 30µA optimize efficiency under all load conditions.

The ISL91127 and ISL91127IR support 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 ISL91127 is available in a 20 bump, 0.4mm pitch WLCSP (2.15mmx1.74mm) package, and 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.


  • 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
  • Continuous output current: up to 2.1A (PVIN = 2.5V, VOUT
  • 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
  • Small 2.15mmx1.74mm WLCSP




  • 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


Type Title Date
Datasheet PDF 1.01 MB
Brochure PDF 5.49 MB 日本語
Datasheet PDF 1.50 MB
White Paper PDF 572 KB 简体中文
Application Note PDF 592 KB
Application Note PDF 509 KB
Application Note PDF 397 KB
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