Buck-Boost Charge Pump based DC-DC converter

A dual mode buck-boost charge pump is presented in this paper. The two modes, buck and boost, of the CP can be used by the same circuit for degrading or elevating the output voltage, respectively, compared to the input. Each mode can be achieved by switching only the input-output connections without any other change in the design of the DC-DC converter. This dual mode configuration aims to merge two different functions into one circuit minimizing the area the DC-DC converter occupies on the die. The proposed buck-boost CP has been designed using TSMC 130nm complementary metal-oxide-semiconductor (CMOS) technology providing a 3.3V output voltage from a 2.2V supply voltage when the DC-DC converter operates in boost mode and a 1.6V output voltage from a 3.3V supply voltage in buck mode. A 2uF capacitor has been placed at the output of the CP. For the buck mode, the capacitor of the output must be pre-charged in order for the CP to operate properly.