EMI performance of spread spectrum clock signals with respect to the IF bandwidth of the EMC standard

Spread spectrum clock signals are used in electronic devices to reduce the electromagnetic interference (EMI). In this paper we investigate clock signals with frequency or time interval modulation, by short length sequences of arbitrary waveform. The paper focuses on the viewpoints: 1) analyzing the EMI performance with regard to the IF bandwidth, defined by the EMC standard; and 2) considering application-specific restrictions of clock signal parameters such as frequency range or minimum on and off time. As an application example a DC-DC-converter is treated. The results are compared with modulating sequences generated by chaotic maps.