Abstract:

This paper introduces a new sampling switch used in pipeline ADC.The switch has high-linearity property by using comparator,inverters chains,CMOS switching,and capacitance.In order to improve the Spurious Free Dynamic Range (SFDR),the basic principle is to ensure MOSFET gate voltage to follow the input voltage,thus the voltage across them being a constant value.Finally Flip-around sample-and-hold circuit is used to verify the new switch.Test results show that this new architecture has 91 dB SFDR,which meets the design requirements.

Key words: sample switch;vgs constant;high-linearity