What is the difference between the guard bar and guard ring?

[chang830]

Hi,
I wonder what is the guard bar in layout? What is the difference between the guard bar and guard ring?

Thanks in advance

 

[hung_wai_ming@hotmail.com]

Guard and guard ring

Guard bar/ring should be self-explained in the difference.
Most of the time, guard is drawn as "ring" type, but sometimes, the "ring" is soft-tied and so cannot be fully classified as "ring" and most of the time, to save space, there is no "ring" and just a "bar" to block between blocks

 

[PaloAlto]

Re: Guard and guard ring

You can put it in this way: You can make a ring using 4 bars ;-)

 

[mists]

Guard and guard ring

a question, when will we need double guide ring?

 

[PaloAlto]

Guard and guard ring

When there is risk of having latch-up. Normally in output transistors

 

[leo_o2]

Guard and guard ring

The bar should be a line while the ring usually is a close loop. Usually the ring will be better for noise isolation because it blocks noise in all directions.

 

[mists]

Re: Guard and guard ring

When there is risk of having latch-up. Normally in output transistors

then whether the double guard-ring has better noise isolate, only weakness is wasting area?

 

[forkschgrad]

Re: Guard and guard ring

if your block or devices must be protected on all sides, it's better to use guard ring. that's ideal but if area is an issue, you may not make it a ring.