The body effect describes the changes in the threshold voltage by the change in, the source-bulk voltage. Since the body influences the threshold voltage (when it is not tied to the source), it can be thought of as a second gate, and is sometimes referred to as the "back gate"; the body effect is sometimes called the "back-gate effect".
For an enhancement mode, n-mos MOSFET body effect upon threshold voltage is computed according to the Shichman-Hodges model (accurate for very old technology) using the following equation.
where is the threshold voltage when substrate bias is present, is the source-to-body substrate bias, is the surface potential, and is threshold voltage for zero substrate bias, is the body effect parameter, is oxide thickness, is oxide permitivity, is the permitivity of silicon, is a doping concentration, is the charge of an electron.
Read more about this topic: Threshold Voltage
Famous quotes containing the words body and/or effect:
“The history of work has been, in part, the history of the worker’s body. Production depended on what the body could accomplish with strength and skill. Techniques that improve output have been driven by a general desire to decrease the pain of labor as well as by employers’ intentions to escape dependency upon that knowledge which only the sentient laboring body could provide.”
—Shoshana Zuboff (b. 1951)
“The courage of a great many men, and the virtue of a great many women, are the effect of vanity, shame, and especially a suitable temperament.”
—François, Duc De La Rochefoucauld (1613–1680)