
This foundation course on analog circuit design introduces mosfet fundamentals and small-signal modeling with a graphical approach. It highlights prerequisites in circuits, network theory, control theory, and signals and systems.
Explore conductors, insulators, and semiconductors, focusing on conduction and valence bands, band gaps, and how oxidation and diffusion create n-type and p-type regions.
Explore how pure silicon becomes n-type or p-type through diffusion and doping with phosphorus or boron, including polycrystalline silicon and the resulting capacitor-like structures in mosfet design.
Explain how voltage creates electric fields in MOS structures, driving electron and hole movement, and compare PMOS, NMOS, and CMOS layouts with diffusion, polysilicon, and drain-source structure.
Apply gate voltage to create a conduction channel in the MOSFET by repelling holes and forming electrons beneath the gate, governed by the threshold voltage and body effect.
Explore the IDS-VDS behavior of a MOSFET: below threshold no current, a linear rise with VDS when VGS exceeds Vth, then pinch-off and saturation as VDS increases.
Examine the IDS–VGS curve to see how current behaves in the linear region. In saturation, current follows a quadratic dependence on VGS with W/L, mu_n, and Cox shaping MOSFET performance.
Explore parasitic capacitances in MOSFETs, including junction, overlap, and channel-related gaps between gate, source, drain, and bulk; analyze their behavior in cutoff, linear, and saturation regions.
Analyze channel length modulation in MOSFETs, relate drain current in saturation to region boundaries, and incorporate lambda to model current variation with channel length.
Explore the body effect in mosfet design. Explain how source–bulk potential differences alter threshold voltage, how tying bulk to source removes the effect, and how depletion and inversion layers respond.
Explain ron in the ohmic region, where id grows linearly with vds, and rds in saturation, shaped by channel-length modulation and channel length.
Explore the graphical view of gm, the MOSFET transconductance, and how small-signal changes around a dc bias yield output current in saturation. Learn gm forms and when to apply them.
Explore how gm links small changes in drain current to gate voltage for a MOSFET in saturation, deriving ΔId ≈ gm ΔVgs from the saturation current equation.
Review the dc bias equations for mosfets and apply boundary conditions to identify whether the device operates in cutoff, linear (triode), or saturation regions for amplification.
Explore small signal modeling of a MOSFET in saturation, deriving gm vgs current and ro from channel length modulation, and compare small-signal representations like the T-model and the D-model.
Apply a small-signal MOSFET model to a simple circuit, grounding DC signals, to analyze input and output resistances and gm with a black-box approach. Explore common source, drain, gate.
This course is a foundation for analog circuit design. Focus of the syllabus is to have an intuitive view of the device.
Circuit design in itself is a wide topic. It is not possible to cover all the analog circuit design essentials in a single course . Our attempt in this course is to build on each of these course and create advanced courses . So here we are with our first basic course of MOSFET and its theory for analog design.
Device physics of the MOSFET capturing the semiconductor theory is covered in the course.
To master circuit design concepts , it is necessary to first master the MOSFET and its theory.
Most of time , due to poor understanding of the MOS theory, designing complex circuits is not possible.
The goal of this course if to look at the graphical view and capture the intuition of the MOS theory .
Small signal modelling is needed to derive the small signal parameters . A sound understanding of modelling is essential.
In this course we will look at the modelling of MOSFET graphically and thereby solve some sample circuits.
This course will be a good refresher for Students who are preparing for interviews( Analog Circuit Design, VLSI ).
For professionals in circuit design this can be a good review.
Please do have a look at the sample videos before joining the course.
I look forward to welcome you all to the course. Happy learning .