Dummy transistor compensation of analog MOS switches

Theoretical and experimental results of the clock-feedthrough phenomenon (charge injection) in sample-and-hold circuits using minimum features size transistors of a self-aligned 3 mu m CMOS technology are compared. The lumped RC model of the conductive channel is used and verified in different switch configurations with variable input voltages. Special emphasis is placed on the feasibility and limits of charge cancellation techniques using dummy switches.