Using adaptive current-limit PFM (pulse frequency modulation) control, the ISL9120 switching regulator from Intersil realizes efficiencies of up to 98%, while automatically transitioning between buck and boost modes without significant output disturbance.
The part accommodates a wide input voltage range of 1.8 V to 5.5 V and has an adjustable output voltage range of 1 V to 5.2 V for use with multiple power rails. It is capable of delivering up to 800 mA of output current (VIN = 2.5 V, VOUT = 3.3 V).The ISL9120 comes in a 1.41×1.41-mm wafer-level chip-scale package small enough for use in the connected devices making up the Internet of Things, including wearables, smart phones, smart thermostats, and point-of-sale devices. It requires only a single inductor and very few external components. Quiescent current of 41 µA maximizes light-load efficiency.Intersil Announces High Efficiency Buck-Boost and Boost+Bypass Switching Regulators for Smartphones and TabletsLED-based time-of-flight IC for object detection and distance measurementBuck-boost/boost switching regulators target mobile devicesKeeping Pace with Power Hungry Mobile DevicesLow-cost LCD-bias generator uses main microcontroller as control ICIn addition to an automatic bypass function, a forced bypass power-saving mode can be chosen if voltage regulation is not required. In forced bypass mode, the regulator consumes less than 1 µA of current over its operating temperature range. Under-voltage, short-circuit, and over-temperature protection are standard.
For more detail: Buck-boost regulator achieves high efficiency