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I knwo when you increase the area of a transistor of a circuit, the power consumption will be increased. I just want to know why is that case?

Here is my circuit in spice

enter image description here

Mirage
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    What kind of transistor are we discussing? And are there added contexts in what you are reading that you should include here? – jonk Nov 30 '21 at 21:45
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    In what contexts? Biased how? If I increase the transistor area of the input branch of a current mirror without touching the other branch, power consumption goes down, so this statement is not true in its current unqualified form. – nanofarad Nov 30 '21 at 21:51
  • You need to consider leakage current but that might not only be affected by size. Then there is gate capacitance - the higher this is the more energy required to charge/discharge it. – Kartman Nov 30 '21 at 22:40

1 Answers1

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In your circuit there are multiple aspects of power consumption.

Static power consumption from leakage in the transistors. This is dominated by FET subthreshold consumption (VGS==0). This is dependent on W/L, and also for devices that are slightly longer than minimum side, the VTH increases with channel length slightly, but makes a significant impact on the subthreshold leakage.

Crowbar current -- generally not dominant, but this does depend on the W/L of the switching devices, an the switching frequency.

Input gate capacitance -- this presents a load on the driving devices and larger devices will generate a larger (capacitive) load.

jp314
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