Master Thesis - Voltage Ripple and Noise

Category: Electronics, Electrical Design & Measurements, Engineering Physics

Scope: 2 students completing 30 credits (20 weeks) each

Background
Switch Mode Power Supplies uses switching mechanisms to convert voltage levels and transfer power. The switching results in a ripple at the DC voltage level, which increases and decreases in sync with the switching. The switching in combination with parasitic impedances also causes unwanted ringing and noise. A power supply with low voltage ripple and noise is crucial in most electronic designs. Too much ripple and noise will damage sensitive components. It can also cause interference with sensitive signals and cause unwanted conducted and radiated emissions.

To validate the quality of a design, it is crucial to be able to measure the ripple and noise in a reliable way. Electronic measurements are often a challenge since the measuring technique and equipment can distort the signals. The environment the device under test is in can also add unwanted noise which will give a false measurement result, such as electromagnetic emissions from light fixtures, computers or even other lab equipment. A measurement result that is worse than reality will cause a lot of time and resources being put into solving a false problem. A measurement result that is better than reality may give a false sense of security and result in a suboptimal design.

To provide a more efficient electronic product development process and to guarantee a good electronic design, this thesis will investigate the measurement of ripple and noise.

Goal
The goal of the thesis is to investigate voltage ripple and noise and to provide a guideline on how to measure it in a reliable and repeatable way. To do this, an investigation of voltage ripple and noise and how it is affected by the power supply design and parasitic impedances is needed. Furthermore, evaluations of various measurement techniques are going to be done both practically, theoretically and with the help of simulations. An investigation of sensitive components on the market and their actual ripple and noise requirements, as well as ripple specifications from power supply designers will also be performed.

OK, I am interested! What do I do now?
You are valuable to us – how nice that you are interested in one of our proposals! There are a few things for you to keep in mind when applying.

• Applications are accepted in both Swedish and English, and you apply via the proposal advert.
• The announced theses are open only to students affiliated with a Swedish university/college either directly or via an exchange program.
• When the thesis proposal states that it includes two students working together, we would like you to apply in pairs. In these cases, send one application each but make sure to clearly state in your application who your co-applicant is. If you have any questions regarding this, please do not hesitate to contact us.
• Please attach your CV and University/college grade summary. 

We look forward to hearing from you!

Contact information
For more information please contact Oscar Ridell at 046 272 3833 or Mathias Andersson at 046 272 2004.