steps involved in designing an optimal pad ring

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steps involved in designing an optimal pad ring

Post by Vijay » Wed May 07, 2014 3:03 pm

What are the steps involved in designing an optimal pad ring?

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Re: steps involved in designing an optimal pad ring

Post by Narveer » Wed May 07, 2014 5:38 pm

Steps involved in designing an optimal padring:
1. Make sure you have corner-pads, across all the corners of the padring, This is mainly to have the power-continuity as well as the resistance is less.
2. Ensure that the Padring full-fills the ESD requirement, Identify the power-domains,split the domains, Ensure common ground across all the domains.
3. Ensure the padring has full-filled the SSN(Simultaneous Switching Noise) requirement.
4. Placing Transfer-cell Pads in the cross power-domains, for different height pads, tohave rail connectivity.
5. Ensure that the design has sufficient core power-pads.
6. Choose the Drive-strenght of the pads based on the current requirements,timing.
7. Ensure that there is separate analog ground and power pads.
8. A No-Connection Pad is used to fill out the pad-frame if there is no requirement for I/O's.Extra VDD/GND pads also could be used. Ensure that no Input/output pads are used with un-connected inputs, as they consume power if the inputs float.
9. Ensure that oscillator-pads are used for clock inputs.
10. In-case if the design requirement for source synchronous circuits, make sure that the clock and data pads are of same drive-strength.
11. Breaker-pads are used to break the power-ring, and to isolate the power-structure across the pads.
12. Ensure that the metal-wire connected to the pin can carry sufficient amount of the current, check if more than one metal-layer is necessary to carry the maximum current provided at the pin.
13. In case if required , place pads with capacitance.related information.

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