Is ERC checks are really dangerous..

[bsrin]

Hi All,
I want to know , is the ERC checks are really dangerous that we need to take care or clear the erc errors. I have some ptransistors for which bulk connected to ground. I have lvs clean but not erc.
Giving error like..
"ntap connected to GROUND"

What to do?
what is erc(electrical rule check)?
Please give me some information about these topics.

Thanks in Advance.
bsrin

 

[erikl]

I want to know, is the ERC checks are really dangerous that we need to take care or clear the erc errors.

You're lucky to have run ERC!

I have some ptransistors for which bulk connected to ground.
I have lvs clean but not erc. Giving error like.. "ntap connected to GROUND"

This is a fatal error, if these ptransistors are used as transistors (and not as capacitors), because in this case their sources and drains would be short-circuited via forward-biased diodes to GND. This is a killing scenario!
The LVS can be clean, if the schematic contains the same fatal error.

What to do?

The bulk (ntap) of active ptransistors must have (at least) the highest potential of both their sources & drains, or VDD level, if possible.

what is erc(electrical rule check)?

Yes.

 

[bsrin]

Hi erikl,
I have the pfet with gate , source, bulk connected to ground. So that , i am getting the erc error like " ntap connected to ground ". I asked the designer about these transistor and told that yes these pfet should have bulk connection to ground.
Can i ignore this erc error.....
what to do?

 

[erikl]

Hi erikl,
I have the pfet with gate , source, bulk connected to ground. So that , i am getting the erc error like " ntap connected to ground ". I asked the designer about these transistor and told that yes these pfet should have bulk connection to ground.
Can i ignore this erc error.....

Yes, in this case you can ignore it!

what to do?

Nothing, it's ok!

 

[bsrin]

Many Thanks erikl........

 

[erikl]

Many Thanks erikl........

You are welcome!

I have the pfet with gate , source, bulk connected to ground.

And I hope, the drain also! Otherwise it will be short-circuited to GND, too! And also any other active device in the same nwell.