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Question 4.4: Find VDS and VGS in Figure 4–12 . For the particular JFET in...

Find V_{DS} and V_{GS} in Figure 4–12. For the particular JFET in this circuit, the internal parameter values such as g_{m} , V_{GS(off)} , and I_{DSS} are such that a drain current I_{(D)} of approximately 5.0 mA is produced. Another JFET, even of the same type, may not produce the same results when connected in this circuit due to variations in parameter values.

4.4
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V_{S} = I_{D} R_{S} = (5.0 mA)(220 Ω ) = 1.10 V

V_{D} = V_{DD}  –   I_{D} R_{D} = 10 V – (5.0 mA)(1.0 kΩ) = 5.00 V

Therefore,

V_{DS} = V_{D}  –  V_{S} = 5.00 V – 1.10 V = 3.90 V

and

V_{GS} = V_{G}  –  V_{S} = 0 V – 1.10 V = -1.10 V

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