ISL91108

High Efficiency Buck-Boost Regulator with 4.2A Switches

OVERVIEW

The ISL91108 is a highly-integrated buck-boost switching regulator that accepts input voltages either above or below the regulated output voltage. Unlike other buck-boost regulators, this regulator automatically transitions between operating modes without significant output disturbance.

This device is capable of delivering up to 2.7A of burst current (PVIN = 3V, VOUT = 3.3V), and provides excellent efficiency due to its fully synchronous 4-switch architecture. No load quiescent current of only 27.5µA also optimizes efficiency under light-load conditions. Forced PWM and/or synchronization to an external clock may also be selected for noise sensitive applications.

The ISL91108 is designed for standalone applications and supports a 3.3V fixed output voltage or variable output voltages with an external resistor divider. Output voltages as low as 1V or as high as 5.2V are supported using an external resistor divider.

The ISL91108 requires only a single inductor and very few external components. Power supply solution size is minimized by a 2.34mm x 1.72mm WLCSP and a 2.6MHz 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
  • Output current: up to 1.6A DC (PVIN = 2.8V, VOUT = 3.3V)
  • Burst current: up to 2.7A (PVIN = 3V, VOUT = 3.3V, tON<600µs, t = 4.6ms)
  • High efficiency: up to 95%
  • 27.5µA quiescent current maximizes light load efficiency
  • 2.6MHz switching frequency minimizes external component size
  • Selectable forced PWM mode and external synchronization
  • Fully protected for short-circuit, over-temperature, and undervoltage
  • Small 2.34mm x 1.72mm WLCSP

BLOCK DIAGRAM

 Block Diagram

PARAMETRICS

Parameters
ISL91108
Basic Information
Production Status
Mass Production
iSim Model
YES
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)
1.6
IQ
27.5 µA
Switching Freq. (max) (MHz)
2.9
Switching Freq. (min) (MHz)
2.4
Max Duty Cycle (%)
-
Qualification Level
Standard
Peak Efficiency (%)
95
POR
Yes
SYNCH Capability
Yes
Control Type
Current Mode
Switching Frequency Range (MHz)
2.4 to 2.9MHz
Can Sample
YES
Temperature Range
-40 to +85

Confirm below disclaimers

Input Renesas account name and password