Abstract: A low-distortion high-bandwidth bootstrap analog switch suitable for high-speed signal transmission is presented. The gate-to-source voltage of the switch is set by the combined on-voltage of a PMOS and an NMOS, and the difference between the gate-source voltage and the threshold voltage (V_GST) of the switch is constant with a rail-to-rail input, with the body effect also nearly canceled. Implemented in the TSMC 0.18μm CMOS process, results from HSPICE simulation show that the V_GST is nearly constant with the input ranging from 0 to 1.8V, and that the -3dB bandwidth is larger than 10GHz. When the input frequency is 1.5GHz, and full-scale range is 0.8V, the output can follow the input nearly without attenuation, and its SFDR(spurious free dynamic range) is 65.4dB.

Key words: low distortion, high frequency, rail-to-rail, switch, bootstrap