On the Web

I found no key entrainment papers or websites on the Web. However, you can use search engines such as Google and Google Scholar to find related information on the Web as well as IEEE Xplore. You might want to explore with the following keywords combined with "power supplies".

• synchronization
• entrainment

I found tens of thousands of hits, with nothing useful in the first 20 results except this Web site and a reference to a graduate course in nonlinear circuits in the University of California, Berkeley catalog. A large number of the hits are related to medicine, fluid dynamics, and the impact of power supply noise on clock jitter.

Do not use this information for design without independent verification of the information.

Editor: Jerrold Foutz

On the Web

I found no key entrainment papers or websites on the Web. However, you can use search engines such as Google and Google Scholar to find related information on the Web as well as IEEE Xplore. You might want to explore with the following keywords combined with "power supplies".

• synchronization
• entrainment

I found tens of thousands of hits, with nothing useful in the first 20 results except this Web site and a reference to a graduate course in nonlinear circuits in the University of California, Berkeley catalog. A large number of the hits are related to medicine, fluid dynamics, and the impact of power supply noise on clock jitter.

Do not use this information for design without independent verification of the information.

Editor: Jerrold Foutz

Personal Anecdote

A group of us started playing with switching-mode power supplies in the early 1960's. One of the engineers with whom I worked, Paul Beihl, who had spend a summer as an engineering student in Austria, found a buck converter described in a German language engineering magazine he subscribed to. Several us started to build breadboards and play with the circuits.

My first design was a buck converter operating at 1 kHz using a Germanium "door knob" 2N174 transistor. About a year later a germanium power transistor became available that would switch at higher frequency. We tried our first production design with hysteretic converters operating at a nominal 12 kHz (yes you could hear them and they annoyed virtually everyone.)

Solution

Analysis and simulation are not helpful for practical design schedules due both to the complexity of the mathematics for analysis and the time and resources to simulate accurately. The only practical method of discovering frequency entrainment is testing for it -- and you may not catch everything. What follows are a few practical suggestion to improve the probability that your power supply design will not entrain.

Here is the way I test for it. Load transients are used in the description, but testing for line transients and transients on the reference are similar. Don't forget to also test for these.