The ISL91110 is a high-current buck-boost switching regulator

for systems using new battery chemistries. It uses Intersil’s

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 ISL91110 is 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. Its fully

synchronous low ON-resistance 4-switch architecture and a low

quiescent current of only 35µA optimize efficiency under all load

conditions.

The ISL91110 supports standalone 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 ISL91110 is available in a 25-bump, 0.4mm pitch WLCSP

(2.33mmx2.07mm) and a 2.5MHz switching frequency, which

further reduces the size of external components.

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 2A (PVIN = 2.5V, VOUT = 3.3V)

• Burst current: up to 3A (PVIN = 3V, VOUT = 3.3V, tON < 600µs,

t = 4.6ms)

• High efficiency: up to 96

• 35µA quiescent current maximizes light-load efficiency

• 2.5MHz switching frequency minimizes external component

size

• Fully protected for short-circuit, over-temperature, and

undervoltage

• Small 2.33mmx2.07mm WLCSP

Applications

• Brownout free system voltage for smartphones and tablet PCs

• Wireless communication devices

• 2G/3G/4G RF power amplifiers