Charge Injection Cancellation

[khalil07]

charge injection cancellation

Please I want to help me to solve the Charge Injection Cancellation I try the dummy transistor is not beneifit. I design a sample and hold phase detector and the O/P was affected by this problem

 

[safwatonline]

signal dependent charge injection

bottom plate sampling

 

[khalil07]

differential charge injection cancellation

what do you mean by that

 

[safwatonline]

bottom-sampling charge injection

bottom plate sampling is a technique used to prevent signal dependent charge injection and introduce instead a common mode offset which is removed if working in a differential manner
please refer to any ADC course

 

[lladnar23]

Read about it in Johns & Martin or in Razavi (I think). Basically you disconnect the bottom of the sampling cap before disconnecting the input voltage -- then the charge injection is not signal dependent, so it doesn't matter as much for overall linearity, etc...