Novel transformer shielding concept intended for data communication

Transformers are among the most critical components in data communication equipment. This paper discusses the EMC related parameters of pulse transformers, the common approach of manufacturing them with toroids and the disadvantages of this construction. As the data rate of communication migrates to 100 Mbit/sec, the demand for higher quality transformers becomes more apparent. The vital information regarding the performance of a device at high frequencies is often misinterpreted from the manufacturer´s data sheets. This paper discusses various testing setups to assure proper EMC quality of magnetics. A new concept of constructing transformers for data communication on E-E cores is explored. Test data, supporting improved transformer common mode attenuation utilizing an internal shield, is presented