ISL91127

High Efficiency Buck-Boost Regulator with 4.5A Switches

OVERVIEW

The ISL91127 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 ISL91127 can deliver at least 2.1A 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 ISL91127 supports 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 1V or as high as 5.2V are supported.

The ISL91127 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
  • Input voltage range: 1.8V to 5.5V
  • Continuous output current: up to 2.1A (PVIN = 2.5V, VOUTHigh 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

BLOCK DIAGRAM

 Block Diagram

PARAMETRICS

Parameters
ISL91127
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
Output Voltage Max (V)
5.2
Output Current Max (A)
2.1
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

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