Linear Regulator in Closed Loop Operation

The goal of this lab is to analyze the closed loop operation of a linear regulator. We investigate the impact of the loop gain on the ability to reject noise and changes in the output voltage, which is the most important feature of linear regulators. First, we will review the principle of operation and the simplified model of a closed loop linear regulator. Next, we will use the simplified model to predict its response to AC perturbations and its accuracy to the reference signal. Then, we will simulate the linear regulator in DC and AC operation to evaluate the impact of the MOSFET and error amplifier parameters. Finally, we will perform experimental tests with a real linear regulator, and will compare the results of simulations and measurements to verify their consistency.
by Dr. Nicola Femia | University of Salerno, and Texas Instruments
This is module 4 of 12 in the course, Power Electronics.


After completing this lab, students will be able to:
  1. Given a linear regulator and its MOSFET and error amplifier characteristics, calculate the DC operating point and the AC response to input and reference voltage perturbations, with specified units and accuracy, by applying the appropriate theoretical formulae.
  2. Given a linear regulator and its MOSFET and error amplifier characteristics,simulate the DC and AC operation with different error amplifier configurations, to determine the accuracy of theoretical model predictions, by comparing the appropriate sets of data and results
  3. Given a real linear regulator, a dynamic power supply, and a function generator, measure the accuracy of the DC output voltage with respect to the desired nominal value, you will determine the AC response of the linear regulator, and you will determine the elements influencing the accuracy of simulations, by comparing the appropriate sets of data and results.


  • Basic proficiency using Multisim Live
  • Basic proficiency using ELVIS III Instruments
  • Basic proficiency in circuits and analog electronics


Engineering laboratory solution for project-based learning that combines instrumentation and embedded design with a web-driven experience, delivering a greater understanding of engineering fundamentals and system design.

Multisim Live

Multisim Live is an online, touch-optimized component of Multisim, so students can design and simulate their circuits anywhere, anytime, on any device.

TI Power Electronics Board for NI ELVIS III

Application board for NI ELVIS III which provides a hands-on approach to power electronics using functional blocks and TI circuits to understand each component in a power electronics system.

Required Software

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Required Hardware

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