Integrated non-inverting buck-boost DC-DC converter with average-current-mode control

With the increasing use of electrical portable devices, an efficient power management solution is needed to extend the battery life. Generally, basic switching regulators, such as buck and boost converters, are not capable of using the entire battery output voltage range. In this work, a non-inverting buck-boost dc-dc converter which can use the full-range output voltage (i.e., 2.5-4.7 V) of a Li-ion battery is proposed. Moreover, average-current-mode control is adopted to improve noise immunity. The die area of this chip is 1.9×1.7mm², and it was fabricated by using TSMC 0.35μm 2P4M 5V mixed-signal polycide process. The input range of the converter is 2.5-5 V, and its output is set to 3.3V. It can supply up to 300 mA load current.