This textbook is built upon a deliberately simplified, yet rigorous, methodological framework. Its primary objective is to enable students to develop a deep and operational understanding of the fundamental building blocks of CMOS analog integrated circuits through analytical reasoning, supported and validated by circuit simulation. The emphasis is placed not on exhaustive modelling accuracy, but on clarity, consistency, and the ability to derive meaningful results through systematic hand calculations. As a pedagogical choice, the author's approach allows the derivation of closed-form expressions for key circuit parameters, facilitates a clear understanding of the relationships between design variables, and supports the development of engineering intuition.   A distinctive feature of this book is the systematic integration of analytical calculations with circuit simulation. All circuits presented throughout the text are implemented and verified using LT Spice, with consistent device parameters and supply voltages. The reader is encouraged not only to follow the theoretical derivations, but also to compare them directly with simulation results. To support this learning process, all simulation files are made available to the reader. This enables immediate experimentation, encourages active engagement with the material, and facilitates independent exploration beyond the examples provided in the text. The combination of analytical rigor and hands-on simulation is intended to bridge the gap between theoretical understanding and practical circuit design.   Provides a simplified, analytical framework for CMOS analog ICs based on first-order transistor models; Enables full verification of analytical results through direct comparison with LT Spice simulations; Includes ready-to-use LT Spice schematics, allowing students to run simulations and explore circuit behavior.