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11.8: Exercises

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    11.8.1: Analysis Problems

    1. For the amplifier of Figure \(\PageIndex{1}\), determine \(Z_{in}\) and \(A_v\). \(I_{DSS}\) = 12 mA, \(V_{GS(off)}\) = −2 V, \(V_{DD}\) = 15 V, \(R_G\) = 220 k\(\Omega\), \(R_D\) = 2 k\(\Omega\), \(R_L\) = 3.3 k\(\Omega\), \(R_S\) = 330 \(\Omega\).

    2. For the amplifier of Figure \(\PageIndex{1}\), determine \(Z_{in}\) and \(V_{out}\). \(V_{in}\) = 50 mV, \(I_{DSS}\) = 15 mA, \(V_{GS(off)}\) = −3 V, \(V_{DD}\) = 20 V, \(R_G\) = 270 k\(\Omega\), \(R_D\) = 2 k\(\Omega\), \(R_L\) = 6.8 k\(\Omega\), \(R_S\) = 270 \(\Omega\).

    clipboard_e3fdcc34eaf831a5ac8d713c81ab6acf7.png

    Figure \(\PageIndex{1}\)

    3. For the amplifier of Figure \(\PageIndex{2}\), determine \(Z_{in}\) and \(V_{out}\). \(V_{in}\) = 60 mV, \(I_{DSS}\) = 10 mA, \(V_{GS(off)}\) = −3 V, \(V_{DD}\) = 20 V, \(V_{SS}\) = −6 V, \(R_G\) = 270 k\(\Omega\), \(R_D\) = 2 k\(\Omega\), \(R_L\) = 4 k\(\Omega\), \(R_S\) = 1.8 k\(\Omega\), \(R_{SW}\) = 200 \(\Omega\).

    clipboard_e8fac049eda4c7e25b6ff6b2a16ac664b.png

    Figure \(\PageIndex{2}\)

    4. For the amplifier of Figure \(\PageIndex{2}\), determine \(Z_{in}\) and \(A_v\). \(I_{DSS}\) = 12 mA, \(V_{GS(off)}\) = −2 V, \(V_{DD}\) = 18 V, \(V_{SS}\) = −4 V, \(R_G\) = 330 k\(\Omega\), \(R_D\) = 2.2 k\(\Omega\), \(R_L\) = 10 k\(\Omega\), \(R_S\) = 3 k\(\Omega\), \(R_{SW}\) = 100 \(\Omega\).

    5. For the amplifier of Figure \(\PageIndex{3}\), determine \(Z_{in}\) and \(A_v\). \(I_{DSS}\) = 12 mA, \(V_{GS(off)}\) = −2 V, \(V_{DD}\) = 18 V, \(V_{EE}\) = −4 V, \(R_G\) = 390 k\(\Omega\), \(R_D\) = 2.2 k\(\Omega\), \(R_E\) = 1 k\(\Omega\), \(R_L\) = 20 k\(\Omega\).

    clipboard_e3bf36c683e3e2a9f65f1e4f189eb425e.png

    Figure \(\PageIndex{3}\)

    6. For the amplifier of Figure \(\PageIndex{3}\), determine \(Z_{in}\) and \(V_{out}\). \(V_{in}\) = 70 mV, \(I_{DSS}\) = 12 mA, \(V_{GS(off)}\) = −2 V, \(V_{DD}\) = 18 V, \(V_{EE}\) = −4 V, \(R_G\) = 390 k\(\Omega\), \(R_D\) = 2.2 k\(\Omega\), \(R_L\) = 20 k\(\Omega\).

    7. For the circuit of Figure \(\PageIndex{4}\), determine \(Z_{in}\) and \(A_v\). \(I_{DSS}\) = 12 mA, \(V_{GS(off)}\) = −2 V, \(V_{DD}\) = 10 V, \(R_G\) = 220 k\(\Omega\), \(R_L\) = 3.3 k\(\Omega\), \(R_S\) = 330 \(\Omega\).

    clipboard_ea86c0336606bf76f5c75bf31d4903588.png

    Figure \(\PageIndex{4}\)

    8. For the circuit of Figure \(\PageIndex{4}\), determine \(Z_{in}\) and \(V_{out}\). \(V_{in}\) = 200 mV, \(I_{DSS}\) = 15 mA, \(V_{GS(off)}\) = −3 V, \(V_{DD}\) = 12 V, \(R_G\) = 270 k\(\Omega\), \(R_L\) = 1.8 k\(\Omega\), \(R_S\) = 270 \(\Omega\).

    9. For the circuit of Figure \(\PageIndex{5}\), determine \(Z_{in}\) and \(V_{out}\). \(V_{in}\) = 100 mV, \(I_{DSS}\) = 10 mA, \(V_{GS(off)}\) = −3 V, \(V_{DD}\) = 15 V, \(V_{SS}\) = −6 V, \(R_G\) = 470 k\(\Omega\), \(R_L\) = 4 k\(\Omega\), \(R_S\) = 1.8 k\(\Omega\).

    clipboard_ee7531d327597e07aea9b2ea12144dad9.png

    Figure \(\PageIndex{5}\)

    10. For the circuit of Figure \(\PageIndex{5}\), determine \(Z_{in}\) and \(A_v\). \(I_{DSS}\) = 18 mA, \(V_{GS(off)}\) = −2 V, \(V_{DD}\) = 14 V, \(V_{SS}\) = −6 V, \(R_G\) = 360 k\(\Omega\), \(R_L\) = 10 k\(\Omega\), \(R_S\) = 1 k\(\Omega\).

    11. For the circuit of Figure \(\PageIndex{6}\), determine \(V_{out}\). \(V_{in}\) = 100 mV, \(r_{DS(on)}\) = 50 \(\Omega\), \(r_{DS(off)}\) = 1 M\(\Omega\), \(V_{GS(off)}\) = −3 V, \(V_C\) = −6 V, \(R_G\) = 270 k\(\Omega\), \(R_D\) = 6.8 k\(\Omega\).

    12. For the circuit of Figure \(\PageIndex{6}\), determine \(V_{out}\). \(V_{in}\) = 100 mV, \(r_{DS(on)}\) = 75 \(\Omega\), \(r_{DS(off)}\) = 750 k\(\Omega\), \(V_{GS(off)}\) = −3 V, \(V_C\) = 0 V, \(R_G\) = 180 k\(\Omega\), \(R_D\) = 5.1 k\(\Omega\).

    clipboard_e598a160171e6255eb9919aaaf4de0435.png

    Figure \(\PageIndex{6}\)

    11.8.2: Design Challenge Problems

    13. Following the circuit of Figure \(\PageIndex{2}\), design an amplifier with a gain of at least 4 and an input impedance of at least 300 k\(\Omega\). \(R_L\) = 10 k\(\Omega\). The JFET has the following parameters: \(V_{GS(off)}\) = −2 V, \(I_{DSS}\) = 15 mA. Try to use standard resistor values.

    14. Using the circuit of Figure \(\PageIndex{4}\), design a follower with a gain of at least 0.7 and an input impedance of at least 500 k\(\Omega\). \(R_L\) = 1 k\(\Omega\). The JFET has the following parameters: \(V_{GS(off)}\) = −3 V, \(I_{DSS}\) = 20 mA. Try to use standard resistor values.

    11.8.3: Computer Simulation Problems

    15. Utili\(Z_{in}\)g manufacturer's data sheets, find devices with the following specifications (typical) and verify them using the measurement techniques presented in the prior chapter. Device 1: \(V_{GS(off)}\) = −2 V, \(I_{DSS}\) = 15 mA. Device 2: \(V_{GS(off)}\) = −3 V, \(I_{DSS}\) = 20 mA.

    16. Using the device model from the preceding problem, verify the design of Problem 13.

    17. Using the device model from Problem 15, verify the design of Problem 14.

    This page titled 11.8: Exercises is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by James M. Fiore via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.