Abstract: A method and apparatus for enabling the operative association of electronic devices that each employ spread spectrum EMI noise reduction. The method includes the detection of frequency modulation and the generation of a modulation detection signal that conveys the modulation extent and type. The modulation detection signal is then used to accommodate the modulation technique and make it compatible with the receiving electronic device. The apparatus of the invention includes an FM modulator that creates an FM signal from an input signal, an FM detector that detects the FM content of the incoming signal and represent this information by means of either voltage or current signals, and a circuit to process this FM information and perform functions such as modification of the FM content and generating a new signal with this new content, complete removal of the content, and “no-action,” whereby the signal is passed on with no alteration to the content.

Abstract: A method for applying spread spectrum noise reduction techniques to USB specifically USB2.0 communications systems includes the step of generating a base (seed) frequency for the USB system, modulating the base (seed) frequency with a spread spectrum (SS) characteristic, and utilizing (as-is, not modified) the existing ASIC that multiplying the now modulated base (seed) frequency to generate the USB standard frequency signaling rate of 480 MHz with the SS characteristic within the USB standard specification for frequency deviation.

Abstract: A method and apparatus for frequency modulating a PWM involves 1) generating a high frequency carrier signal much greater in frequency than the PWM signal; 2) modulating the high frequency signal to generate a spread spectrum carrier signal; and, 3) retiming a PWM signal with this high frequency SS carrier signal so that the binary transitions of the PWM signal are aligned with the frequency varying carrier signal. In another embodiment, a PWM oscillator is driven by a second, FM oscillator having spread spectrum characteristics. In another embodiment a PWM oscillator is driven and modulated by a counter/frequency divider comprised of modules.

Abstract: A controllable delay clock buffer that provides spread spectrum modulation of the output signals with zero cycle slip includes a PLL having a PLL loop filter that comprises an RC network. A clock signal is input to the PLL, and a SS modulation frequency is injected into the capacitor of the PLL loop filter. The SS signal is provided by a secondary charge pump that produces a programmable waveform such as a square wave or a stair case square wave current signal. The programmable waveform is integrated by the loop filter capacitor to form a corresponding triangular or trigonal waveform which varies the input to the VCO of the PLL to define a frequency modulation profile that has a corresponding triangular or trigonal envelope. The bandpass profile of the SS modulation signal is at a higher frequency range than the lowpass profile of the PLL, so that the SS waveform profile is not distorted or cancelled by the PLL.

Abstract: A method and apparatus for frequency modulating a PWM involves 1) generating a high frequency carrier signal much greater in frequency than the PWM signal; 2) modulating the high frequency signal to generate a spread spectrum carrier signal; and, 3) retiming a PWM signal with this high frequency SS carrier signal so that the binary transitions of the PWM signal are aligned with the frequency varying carrier signal. In another embodiment, a PWM oscillator is driven by a second, FM oscillator having spread spectrum characteristics. In another embodiment a PWM oscillator is driven and modulated by a counter/frequency divider comprised of modules.

Abstract: A method for applying spread spectrum noise reduction techniques to USB specifically USB2.0 communications systems includes the step of generating a base (seed) frequency for the USB system, modulating the base (seed) frequency with a spread spectrum (SS) characteristic, and utilizing (as-is, not modified) the existing ASIC that multiplying the now modulated base (seed) frequency to generate the USB standard frequency signaling rate of 480 MHz with the SS characteristic within the USB standard specification for frequency deviation.

Abstract: A method and apparatus for frequency modulating a PWM involves 1) generating a high frequency carrier signal much greater in frequency than the PWM signal; 2) modulating the high frequency signal to generate a spread spectrum carrier signal; and, 3) retiming a PWM signal with this high frequency SS carrier signal so that the binary transitions of the PWM signal are aligned with the frequency varying carrier signal. In another embodiment, a PWM oscillator is driven by a second, FM oscillator having spread spectrum characteristics. In another embodiment a PWM oscillator is driven and modulated by a counter/frequency divider comprised of modules.

Abstract: An oscillator generates a signal that is applied to one input of a phase shifter circuit. The other input of the phase shifter is connected to a source of a phase modulation signal. In response to the phase modulationsignal, the phase shifter provides a clock signal with a spread spectrum.