A High-Voltage Analog Switch Based on Thin Gate Oxygen Process

In recent years, analog switches have been widely used in various fields. Traditionally, high-voltage analog switches are designed based on thick gate oxygen process. Although the structure is simple, its performance is poor. This paper proposes a new high-voltage analog switch circuit based on thin gate oxygen process. The high-voltage analog switch can transmit signals from rail to rail. The structure can be divided into three parts, namely the transmission gate composed of high-voltage NMOS and high-voltage PMOS, the control circuit of high-voltage NMOS and the control circuit of high-voltage PMOS. In addition, based on this structure, an eight-choice high-voltage analog switch is designed, using a 0.18um BCD process. The size of the chip is 1.75mm*1.85mm. The simulation results show that the on-resistance of the switch is less than $5\Omega$ and its bandwidth is more than 400MHz.