Is it necessary to connect the currrent shieldings with ground?

[jarillak]

Is it necessary to connect the currrent shieldings with ground?

Is there any specific reason for this action?
can anyone explain about the current shieldings?

 

[chuckey]

can you explain what you mean by "current shieldings"?
Frank

 

[jarillak]

In analog layout,
current shielding is a technique which is used to by-pass a sensitive signals from one place to another place.For example if we pass a current (in nA or uA).that current line was superimposed near-by metals.

 

[pstuckey]

I'm not sure I understand your question precisely, but in almost all cases a shield needs to have a low impedance path to ground to function properly. A shield that is not connected to ground (or is connected, but with too high impedance) can make things worse.

 

[Kral]

I believe that the "Current Shieldings" you are refering to are also known as "guard bands" . Guard bands should be connected to the same potential as the sensitive circuit point you are trying to protect. For example, if the sensitive point is the inverting input of a simple inverting amplifier, then the guard band should connect to ground. If, the sensitive point has a DC bias voltage, then the guard band should connect to a potential equal to the DC bias. This ensures that there will be no steady state current flow between the sensitive point and the guard band.