AN2934

Comparison of EMI for single and dual output device with and without shield

Doc ID 15394 Rev 1

21/27

6

Comparison of EMI for single and dual output device

with and without shield

Figure 15.

Comparison of EMI for single output with and without shield

The readings in the above plot are of 3 max and hold (scanned three times, with the graph

displaying the highest reading).

The green trace is the dual output transformer with a wire shield and efficiency of 75.7%.

The blue trace is the dual output without shield but with an efficiency of 81.2%. The choice

has been made to go with the regular, non-shielded transformer since it is still 5 db under

the peak limit with better efficiency.

Figure 13.

Dual output with shielded

transformer

Figure 14.

Dual output without shielded

transformer

AM03427v1

AM03428v1

AM03429v1