Circuit and method for minimizing electromagnetic emissions

摘要

A circuit and method for minimizing electromagnetic emissions which employ a cancellation signal to produce electromagnetic fields which are opposites of the fields produced by the digital circuit. The circuit and method of the present invention are particularly suited for use in digital systems which produce constant-frequency and constant-amplitude clock signals for driving a circuit load. The circuit includes a cancellation circuit for producing the cancellation signal, which may include the same oscillator used to produce the clock signal. An amplitude-adjust circuit adjusts the amplitude of the cancellation signal, and a phase-adjust circuit adjusts the phase of the cancellation signal.