Study And Design Of Ultra-low-power High-bandwidth Dual-channel Bidirectional SPDT Analog Switch

With the rise in popularity of complex smart devices,there is an increasing demand for high performance analogue switches,for which an ultra-low power,high bandwidth,bidirectional,single knife,double throw analogue switch is designed.The switch is mainly used in portable electronic smart devices and communication systems,and its functions are mainly high-precision data sampling,audio and video switching,etc.Dependent on R&D requirements,this design is based on the Hua Hong Hongli's 0.35 um BCD process technology,research and design of an ultra-low power,high bandwidth dual channel bidirectional SPDT analogue switch presented by this paper.The overall circuit of this analogue switch chip consists of five parts: the level conversion circuit,the MOS switch circuit,the driver circuit,the break-before-pass circuit and the ESD protection circuit.In this analogue switch design,the difficulties of switching channel crosstalk and total harmonic distortion are solved by the isolation process with low threshold devices through a thermal trap design.The power dissipation problem caused by the difference between the elective level and the supply voltage is solved by the power divider bootstrap design.-40°C to 85°C is the operating temperature range of this switch with a single power supply of 1.8V-3.6V.The design was designed by Cadence virtuoso and the circuit was simulated by ADE Spectre to test the onresistance,signal bandwidth,channel crosstalk,off-isolation and total harmonic distortion of the analogue switch and to optimize the circuit based on the simulation results.The circuit was optimized based on the simulation results.After simulation,the minimum on-state resistance of the analog switch is 0.2?,the signal bandwidth is up to 130 MHz,the minimum quiescent current is 543 n A during normal operation,the channel crosstalk and turn-off isolation are-74.8d B and-78 d B respectively,and the total harmonic distortion is only 0.011%,all electrical parameters met the design specifications and the layout was finishsed.