Electronic Circuit Design 3

Course developed by: Alicja Michalowska-Forsyth, Institute of Electronics, TU Graz
Contact: alicja.michalowskanoSpam@tugraz.at

Course Description
This course provides an in-depth introduction to analog circuit building blocks and low-noise design techniques for precision measurement applications. The course focuses on the analysis, design, and simulation of key amplifier architectures, including transconductance amplifiers, transimpedance amplifiers, and precision measurement circuits, with particular emphasis on noise performance and signal integrity. Students study the operating principles of operational transconductance amplifiers (OTAs), current comparators, and transimpedance amplifiers, examining both open-loop and closed-loop configurations. Practical circuit behavior is explored through extensive LTSpice-based simulations using CMOS technology models, enabling students to analyze device-level effects, topology trade-offs, and performance limitations. Precision measurement techniques, including bridge-based circuits and parametric sensitivity analysis, are introduced to highlight accuracy and resolution constraints in real-world sensing systems. A significant portion of the course is dedicated to the fundamentals of noise in electronic circuits, covering noise sources in passive components, MOSFETs, and amplifier stages, as well as their impact on low-level signal processing. Building on this foundation, students examine low-noise amplifier architectures, comparing design approaches such as common-source and common-gate configurations and their suitability for different applications.

Learning Objectives
After successfully completing the course, students will be able to:

• Explain the operating principles of transconductance and transimpedance amplifiers and their role in analog signal conditioning.
• Analyze the behavior of operational transconductance amplifiers (OTAs), current comparators, and transimpedance amplifiers using circuit theory and simulation results.
• Perform and interpret circuit simulations in LTSpice, including open-loop and closed-loop configurations, using CMOS technology models.
• Design and evaluate precision measurement circuits, including bridge-based configurations, with attention to sensitivity, accuracy, and parameter variation.
• Describe the fundamental noise mechanisms in electronic circuits, including noise sources in resistors, MOSFETs, and amplifier topologies.
• Analyze the impact of noise on amplifier performance and signal integrity using both theoretical concepts and simulation-based approaches.
• Compare low-noise amplifier architectures (e.g., common-source versus common-gate) with respect to noise performance and application requirements.
• Design and assess low-noise readout circuits such as low-noise transimpedance and current-to-voltage amplifiers.
• Apply low-noise and precision circuit concepts to real-world application examples, including radiation detector readout systems and high-precision temperature measurement circuits.