fz2101
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Posts: 17
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Hello Everyone,
In many differential designs, there is a question of how to connect the load capacitors. Gm-C is shown below as an example.
In school, we were taught that this question depends on whether die area is a constraint and whether fully symmetric capacitors are available. If fully symmetric capacitors are available, then the capacitance required is 4C for the left configuration and 1C for the one on the right (replace the two series caps with one). However, the loading seen by the common-mode path is 4C on the left and zero on the right, so the common-mode stability is better for the left side configuration.
My question is which configuration do people use in the industry, for what application and for what reason? Any other differences (maybe in terms of linearity, noise, etc.) between these two configurations?
Thanks.
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