Reduction Of EMI Emission To Harnesses
Publication Date: 2003-Jan-31
The IP.com Prior Art Database
The power stage of a power converter is a very strong noise source. Not only does the noise distribute to power buses, it couples to the low-voltage control stage, mainly through stray capacitance. This noise disturbs the controller operation and emits radiated noise to the ambient, mainly from unshielded harnesses. To reduce emission to the harness, small surface-mount or feed-through capacitors are incorporated to each output pin to shun noise to the ground, and the test results have shown significant noise reduction at higher frequencies. However, this approach is not very effective at the lower end (say, below a few MHz), but unfortunately power electronic noise is stronger at this range. To provide better mitigation approach, this disclosure suggests an alternative methodology.