Non-inverting Buck-Boost DC-DC Converter with Three-Mode Selection Circuit

For battery-powered applications where high current conversion efficiency and long battery life are required, non-inverting Buck-Boost converters are considered the best option. However, during mode switching, ripples in the output current and voltage can significantly affect the efficiency of the chip. The novel Non-inverting Buck-Boost DC-DC converter proposed in this study with a three-mode selection circuit selects the different operating modes (three modes) by comparing VIN and VOUT. By this way, the DC-DC converter can reduce the output ripple and instability during operation. The proposed chip was developed and implemented on the CMOS 0.18 µm process. In addition, a high peak efficiency of 97% can be achieved under the conditions of a wide input range of 2.5 V - 5 V.