The ISL91108 is a highly integrated step-down booster switch regulator that accepts input voltage above or below the regulated output voltage. Unlike other buck-boost regulators, this regulator automatically switches between operating modes without significant output disturbance.
Typical fixed output application
ISL91108IINZ efficiency vs output current
The device is capable of delivering bursts of current up to 2.7A (PVIN = 3V, VOUT = 3.3V) and offers excellent efficiency due to its fully synchronized 4-switch architecture. The no-load static current of only 27.5 μA also optimizes the efficiency under light load conditions. Forced-pwm and/or external clock synchronization are also options for noise-sensitive applications.
The ISL91108 is designed for stand-alone applications and supports a 3.3V fixed output voltage or variable output voltage with an external resistance divider. Use external resistance dividers to support output voltages as low as 1V or as high as 5.2V. The ISL91108 requires only an inductor and few external components. The size of the power solution is minimized with a 2.34mmx1.72mm WLCSP and a 2.6MHz switching frequency, which further reduces the size of the external components.
Pin Configuration
Block Diagram
Features
● Accept the input voltage above or below the regulated output voltage
● Automatic and seamless conversion between buck and Lifting mode
● Input voltage range :1.8V to 5.5V
● Output current: up to 1.6A DC (PVIN = 2.8V, VOUT = 3.3V)
● Burst current: Max. 2.7A (PVIN = 3V, VOUT = 3.3V, tON 600µs, t = 4.6ms)
● High efficiency: up to 95%
● 27.5μA static current maximizes light load efficiency
● 2.6MHz switching frequency to minimize external components size
● Optional mandatory PWM mode and external synchronization
● Complete protection against short circuits, overtemperature, and undervoltage
● Small 2.34mm x 1.72mm WLCSP
Applications
● Smartphones and tablets
● Wireless communication equipment
● 2G/3G/4G power amplifier
