The book deepens the understanding of important concepts and elements necessary to properly design an electronic system by exploiting analog, mixed-signal and digital components. The book aims to provide the tools to analyze and develop electronic stages and systems, like: - Performances of Operational Amplifiers - Small and large signal responses of OpAmps; - Frequency compensation of OpAmp stages; - Advanced OpAmps (INA, ISO, Current feedback, Current mode and OTA amplifiers); - Sample&Hold sampling circuits; - Analog mux, digital potentiometers and universal active filters; - Standard and advanced DAC and ADC converters; - Under-and over-sampling; - Sigma-Delta modulators; - Microcontrollers. Many real circuits and exercises are provided at the end of each Chapter and also in two specific Chapters focused on analog electronic systems employing OpAmps and mixed-signal systems with DAC and ADC converters. Most exercises are fully solved, with detailed step-by-step stage design and electronic schematics analysis. The book is addressed to an audience interested in hardware and firmware design of electronic circuits and systems for acquisition, conditioning and conversion of analog and digital signals.