Wednesday, March 25, 2020

Modeling and Practical Design Dual-Mode Sinewave and Common Mode Filter for PWM Motor Drives System Using Tricore Laminations

Tin Luu, MTE, March 25, 2020

A dual-mode sinewave output filter that eliminates motor problems due to the PWM waveforms in both common mode and differential mode operation is proposed. A three-phase inductor constructed with tricore laminations. The windings possess differential mode inductance and proportionally every large common mode inductance characteristic. In voltage source converters, the common mode voltage is mainly distributed in the switching frequency range, therefore the common mode voltage in this filter design is in the medium frequency range referring to the switching frequency and sidebands of its integral multiples. The single integrated inductor with the capacitors creates a LC lowpass filter in both common mode and differential mode operation. This proposed filter offers a complete solution with reliable, practical and cost-effective to the issues caused by common mode voltage in power converter systems. Three different rating of 5A, 45A and 160A prototypes were built, and test results presented.


Monday, March 23, 2020

Getting the Voids Out

MACOM, March 23, 2020

Reducing solder voids is a pervasive challenge affecting the electronics industry.  With higher thermal dissipation requirements placed upon the attachment of a device to a circuit board the number of voids within the solder joint becomes critical.  There are various considerations that need to be taken into account, including 1) the design of the substrate 2) the surface condition of the part being attached 3) the type of solder selected 4) the reflow profile 5) pattern and volume of paste deposition, among others.  Let’s dive further into some of these considerations: