MOS equivalent composite in series connection

[Junus2012]

Hello

I would like to ask your help to answer me about the bulk connection of the equivalent series MOS transistors to one transistor as shown in the attached image. Here I assumed I have a single transistor first, then to make the composition of four transistors in series, the individual aspect ratios are multiplied by four to have the same aspect ratio of the original single transistors

but as you see there is two possibilities of the bulk connection in A and B, which one of them should be the more accurate to have identical result to the single one

Thank you

 

[Dominik Przyborowski]

Body has to be shared for all devices, otherwise it will not work as series parallel equivalent. This is clear if you simply take single transistor and start cutting it for a smaller pieces.

For more details read Bult paper about MOST only current divider, or papers about M-2M ladders.