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    [Moved]: How do you make the cirucit operating in weak inversion region?

    I have this oscillator design and it says it operating at weak inversion region. How do you do that?

    I thought Vgs controls everything whether something in saturation, triode or weak inversion but the block diagram doesn't show Vgs how it could make the device in weak inversion region as opposed to other mode like saturation or triode.

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    Re: How do you make the cirucit operating in weak inversion region?

    You just lower Vdd until it's less than VT, and there you
    are.


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    Re: How do you make the cirucit operating in weak inversion region?

    Just asking.. What would be the application of such an oscillator with transistors biased in the weak inversion region ?



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    Re: How do you make the cirucit operating in weak inversion region?

    Same as any other ring oscillator, only slower and lower
    power. "How low can you go?" is a thing, in the present
    IoT frenzy, that attracts wheel-reinventing research.


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    Re: How do you make the cirucit operating in weak inversion region?

    Quote Originally Posted by sys_eng View Post
    ... Vgs controls everything whether something in saturation, triode or weak inversion but the block diagram doesn't show Vgs how it could make the device in weak inversion region as opposed to other mode like saturation or triode.
    The other way round: weak inversion (or subthreshold) is an operation mode, saturation or triode are operation regions. In weak inversion mode you can still have transistors operating in saturation or in triode (or in off) region.

    For oscillator circuits, where you have transistors switching between saturation and off region, the way how to operate them in weak inversion mode is indicated in dick freebird's post above:
    Vdd < VT


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