Conventional charge pump circuit based on dynamic charge transfer switch (CTS) is limited by its efficiency due to the threshold voltage of MOS transistor. This paper proposes an improved dynamic CTS based charge pump circuit by modifying the conventional circuit architecture at the output stage by a PMOS transistor with appropriate control signals. A four-stage dynamic CTS based charge pump circuit with pumping capacitance of 50 pF, clock frequency of 20MHz and load current of 100µA is designed and simulated in Cadence environment using UMC 0.18µm CMOS technology. As compared to conventional architecture, this modification has reduced the voltage loss at the output to 1.3% as compared to 9% for 1V input and 6% as compared to 20% for 0.3V input voltage. The core dimension of the layout is 750µm×530µm. © Springer Nature Singapore Pte Ltd 2017.