HIGH FREQUENCY MODEL OF MOSFET | ANALOG CIRCUITS | LECTURE 03 BY MR. SHAILENDRA SINGH OJHA | AKGEC

Value of the Information & Strength of the Argument

The lecture provides a solid, step-by-step derivation of key high-frequency parameters for MOSFET amplifiers, which is valuable for students learning analog circuit design. The argumentation is logical and follows standard textbook methodology, such as applying Miller’s theorem and recognizing single-time-constant low-pass behavior. The numerical example reinforces the theoretical concepts and demonstrates practical calculation techniques. However, the presentation is somewhat informal, with occasional verbal slips and approximations that are not always explicitly justified (e.g., neglecting Cgd in the output current calculation). The instructor assumes prior knowledge of BJT high-frequency models, which may limit accessibility for beginners. Overall, the content is accurate and pedagogically useful, though it lacks depth in discussing the physical origins of the capacitances or alternative modeling approaches.

Scientific Rigor, Source Quality, Title Accuracy

The lecture is a tutorial-style presentation without explicit citations to external sources. The instructor relies on standard textbook knowledge, which is generally reliable. The title accurately reflects the content, and the video is part of a structured course playlist. The description provides links to the institution’s website and the course playlist, which serve as sources for further context. The presentation is clear but could benefit from referencing standard textbooks or research papers to enhance scientific rigor. The numerical example is solved correctly, and the derivations follow conventional methods. Overall, the scientific rigor is acceptable for an educational lecture, though it is not a research-level presentation.

The title accurately reflects the content: a lecture on the high-frequency model of MOSFETs within an analog circuits course.

7/10

The lecture provides a clear derivation of the high-frequency MOSFET model, unity-gain frequency, and high-cutoff frequency for a common-source amplifier, with a worked numerical example. The content is technically accurate and follows standard textbook approaches (e.g., Miller effect). However, the presentation is informal, lacks citations, and contains minor verbal slips and approximations that are not always explicitly justified.

Markers derived by PSI from the transcript: the creator did not define chapters.

• 00:30Introduction to the lecture and comparison of low-frequency vs high-frequency behavior of BJT and MOSFET.
• 02:00Presentation of the high-frequency small-signal model of MOSFET, including capacitances Cgs, Cgd, and Cdb.
• 04:00Derivation of the unity-gain frequency fT using the simplified model.
• 07:00Introduction of the common-source amplifier circuit and its high-frequency equivalent.
• 10:00Application of Miller's theorem to find the equivalent input capacitance.
• 13:00Derivation of the high-cutoff frequency fH and the expression for high-frequency gain.
• 16:00Worked numerical example: calculating midband gain, fH, and fz.
• 19:00Discussion on the effect of cascading amplifiers on bandwidth and the formulas for new cutoff frequencies.

• AKGEC Official Website — Institution's official website, providing context for the course and instructor.
• Analog Circuits Playlist — Playlist containing all five units of the Analog Circuits course, including this lecture.

• Sedra and Smith, Microelectronic Circuits — Standard textbook covering high-frequency models of MOSFETs and amplifier analysis.
• Razavi, Design of Analog CMOS Integrated Circuits — Advanced textbook with detailed treatment of high-frequency MOSFET modeling.