On charge injection in analog MOS switches and dummy switch compensation techniques

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