An integrated tri-mode DC-DC converter with segmented power devices and power transmission gate

An integrated high efficiency tri-mode DC-DC converter that can operate in buck, boost and buck-boost configurations is presented. A power transmission gate is implemented in the tri-mode converter as the high side driver of the H-bridge output stage to extend the range of the output voltage to be lower than 1.5 V. The converter also incorporates segmented power output stages with dedicated top level metal layouts according to the direction of the current flow. The ability to select the size of the power transistors allows the optimization of the power conversion efficiency by trading off conduction loss with gate-drive loss over a wide range of output currents. A peak efficiency of 90% is measured in boost mode with V_in = 3.7 V, V_out, = 5 V at 1.5 MHz and a maximum output current of 0.5 A. The proposed integrated converter is implemented using Dongbu HiTek's 0.18μm HVCMOS technology.