Using the three-terminal charge-pump cell, this paper proposes an auxiliary power supply circuit for the control IC of a boost converter. Many technologies have been proposed for supplying the operational power to the control IC; however, their drawbacks include high cost and large size. Therefore, the three-terminal charge-pump cell is developed. Additionally, with the three-terminal charge-pump cell, the application to the boost converter is extended to other converters; these include Cuk, Sepic, forward, flyback, half-bridge and full-bridge converters. In this paper, the auxiliary power supply for the control IC of the boost converter is implemented with the proposed three-terminal charge-pump cell.