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Unformatted text preview: sion • A more fundamental equation is derived
[Tsividis] results in the above equation
• In nonsaturation with Vds = 0, the device is a
resistor so the thermal noise is given by EECS 240 Lecture 5: Noise © 2006 A. M. Niknejad and B. Boser 12 Strong Inversion Noise
• In saturation, the drain current is given by • For a long channel model, you can
substitute gm for the above factor. In
practice the form involving inversion charge
is more accurate and used by SPICE/BSIM.
EECS 240 Lecture 5: Noise © 2006 A. M. Niknejad and B. Boser 13 Weak Inversion
• The origin of noise in weak inversion is
shot noise. So the result should be ~ 2qIDS.
• But using the expression for inversion
charge in weak inversion we get the same
result! (similar to a diode) EECS 240 Lecture 5: Noise © 2006 A. M. Niknejad and B. Boser 14 Thermal Noise for Short Channels
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