hi,

I design a bootstrapped switch used in a simple sample/hold circuit( a bootstrapped switch with a cap load).

The bootstrapped circuit and simulation result is in the following graph.
In the simulation, the blue line is a ideal switch result. the red line is using a bootstrapped switch.

It looks that the charge injection is so large for bootstrapped switch. I can reduce the switch size to decrease the charge injection effect,but it can't be totally removed. If i use a mos switch with a dummy switch, it can works well to remove the charge injection.

My question is, does bootstrapped switch can eliminate the charge injection ? or it can only give a linearity Ron ?

best
Gang