Novel high-voltage, high-side and low-side power devices, whose control circuits are referred to as the tub, are proposed and investigated to reduce chip area and improve the reliability of high-voltage integrated circuits. By using the tub circuit to control a branch circuit consisting of a PMOS and a resistor, a pulse signal is generated to control the low-side n-LDMOS after being processed by a low-voltage circuit. Thus, the high-voltage level-shifting circuit is not needed any more, and the parasitic effect of the conventional level-shifting circuit is eliminated. Moreover, the specific on-resistance of the proposed low-side device is reduced by more than 14.3% compared with the conventional one. In the meantime, integrated low-voltage power supplies for the low-voltage circuit and the tub circuit are also proposed. Simulations are performed with MEDICI and SPICE, and the results show that the expectant functions are achieved well. Novel high-voltage, high-side and low-side power devices, whose control circuits are referred to as the tub, are proposed and investigated to reduce chip area and improve the reliability of high-voltage integrated circuits. Accordingly, the high-voltage level-shifting circuit is not needed any more, and the parasitic effect of the conventional level-shifting circuit is eliminated. In the meantime, integrated low-side device is reduced by more than 14.3% compared with the conventional one. voltage power supplies for the low-voltage circuit and the tub circuit are also proposed. Simulations are performed with MEDICI and SPICE, and the results show that the expectant functions are achieved well.