EMI Reduction Overview
The FCC, EMC, and other international regulations are designed to minimize radiated emissions from electronic equipment. EMI (electromagnetic interference) rules reduce interference between electronic devices and address health and safety concerns.
Designers control radiated emissions by shielding radiating circuitry and cabling systems, bypassing, board layout, and many other techniques. Several Maxim oscillator and clock-generation products include low-EMI designs. A recent development is "spreading," or dithering, the center frequency of clocks used in computers and power supplies to spread radiated emission energy over a band of frequencies, rather than having all the energy emitted at one frequency.
Other EMI-cutting techniques are built into some Maxim components. RS-232 and RS-485 drivers, for example, use sophisticated circuitry to control the slew rate of output signals, reducing harmonics of the carrier frequency. When you select these components, you are employing radiation-reduction techniques automatically!