internal power supply routed through I/O ring -> package

[manojlg]

Why do we usually route power supply for macros / core transistors through I/O ring -> package -> ( board ) -> package -> I/O ring and then to the chip ?

 

[jbeniston]

I'm not so sure this is necessarily 'usually' done.

One reason might be because you need an external cap.

 

[manojlg]

Re: internal power supply routed through I/O ring -> pack

Hi .. Thanks.

I could figure out that the reason also is to allow an external LDO to supply voltage to the whole chip after shutting down the internal LDO. This may be required when we want to do over voltage testing of the chip.