current density...........

[ssankurathri]

hi
could anyone please tell me how to calculate the current density of the device for given physical dimensions?
i mean given length and width of the device, is it possible to get the device current density rating?
all suggestions r welcome.
cheers
skr

 

[rajkumaru]

Hi,
I think foundry itself provide information regarding current rating for each layer so using formula
width of the metal = current rating value for specific metal* length of metal

I am not sure about this formula so Please correct me If I am wrong.

 

[gte582w]

Let's see if it is a wire, then with thickness and width, we can get the
cross area A, if DC current IDC flowing through, the density will be
IDC/A. But if it is RF current, we know that Skin effect will redued the
effective A, then it will be more complicated.

 

[mpkp123]

Hey for the current desity of any device the specifications come from the foundry.
They provide the specification for each layer and it is different for different technologies.

 

[ssankurathri]

hi
am designing a diode.given the length and width of device, is it possible to calculate the current density of the diode? how can we calculate the current withstanding capability of the device for given dimensions?
cheers
skr

 

[muiyuen]

Hi ssankurathri,

If i am not mistaken, the foundry's documents would have the information or formulas that relate the metal layers to their respective current densities...

In my layouts, the width (instead of length) of the metal were made to withstand the required current. For example, from the formulas, if the metal1 of width 0.5u to withstand 1mA, then if your device has the width of 1u (of metal1), it can withstand a maximum of 2mA. If the device is connected to higher metals, then the formulas for the respective metal layer is followed, eg, if metal2 of width 1u to withstand 1mA, then the same device above connected through metal2 would need a width of 2u to withstand the maximum 2mA.

Hope that this helps...

 

[mehboob_iiui]

I think

J=∫I.dA

if I am not forgetting

 

[renwl]

Let's see if it is a wire, then with thickness and width, we can get the
cross area A, if DC current IDC flowing through, the density will be
IDC/A. But if it is RF current, we know that Skin effect will redued the
effective A, then it will be more complicated.

you mentioned the RF current. is it peak current or average current?

 

[tandr]

You can search in the book " art of layout " , in this book , it gives typical
device parameters