What are tap cells ?

[deh_fuhrer]

What are Tap Cells.Could somebody please explain the use of tap cells.

 

[p_shinde]

tap cells for latch up

tapping is done to avoid latch up effect......hope u know latch up effect...

so for that n tap is connected to p transistor....by connecting p tap over VDD

similarly for p tap ....is connected to n transistor....connected to VSS...

hope this helps,

Prasad

 

[eternal_nan]

Tap Cells

I guess you can also say that well taps are placed in order to ensure the substrate/well is kept at vdd/gnd potential or very close to it. Switching circuits dump current into well/substrate and if there is a high resistance between substra/well and the vdd/gnd grids the substrate can be at different potential than vdd/gnd (this cause potential latchup and all sorts of other effects). More taps reduces the resistance.