draw the guard ring or use it from the transistor directly?

[katrin]

I have one question about guard ring.

I can either draw the guard ring by hand or add the guard ring automaticly for each side from transistors' properity.

When I draw the guard ring by hand, just add each layer manually, it is more time-consuming, but it is more flexible. I can leave some small opens for wiring.

The problem with automatic guard ring is that there is no open around the transistors for wiring. So I can only use one or two sides automatic guard ring.

I am wondering usually do people draw the guard ring manually or do you just use the automatic guard ring?

thanks

 

[leohart]

I have the same question about guard ring opening for wiring...

 

[Fom]

For Virtuosso I created ROD and use that.
Because sometimes I need to surround 2, 3 or more transistors by the same guard ring

 

[Teddy]

in general for RF or sensitive devices I would recommend to use guardring / substrate tie for each device. But since each of those cost area you do not have to surround them alway - it's enough to let say have a well/sub tie as a stripe above/bellow devices and surround blocks with guardrings.

 

[Brittoo]

Re: draw the guard ring or use it from the transistor direct

I have one question about guard ring.

I can either draw the guard ring by hand or add the guard ring automaticly for each side from transistors' properity.

When I draw the guard ring by hand, just add each layer manually, it is more time-consuming, but it is more flexible. I can leave some small opens for wiring.

The problem with automatic guard ring is that there is no open around the transistors for wiring. So I can only use one or two sides automatic guard ring.

I am wondering usually do people draw the guard ring manually or do you just use the automatic guard ring?

thanks

hey Katrin

U can do either ways whatever is more convinient and less time consuming. I usually draw the same irrespective of small / large blocks, i find it more flexible.

Regards
Brittoo

 

[fixrouter4400]

Hi Katrin,

What I normally do is to put all the same type of transistors with the same bulk connection and surround it with a full double guardring to be safe and you can use metal2 or higher for device interconnections.

 

[iclayout1001]

Re: draw the guard ring or use it from the transistor direct

Yes, ROD is quite convenient for guardring.

For Virtuosso I created ROD and use that.
Because sometimes I need to surround 2, 3 or more transistors by the same guard ring