On-Chip Substrate Noise Suppression Using Clock Randomization Methodology

We present a method for substrate coupling noise suppression that employs a pseudo-random clock. A pseudo-random sequence is utilized to randomize the pulse train of the system periodic clock effectively decorrelating its discrete spectral tones. Therefore, the discrete portion (spectral spikes) of the power spectral density of the regular clock is dispersed and the continuous (wide-band) portion of the spectrum rises as a noise floor. This work shows that there is a 22dB attenuation of the harmonic power by utilizing the clock randomization method with respect to the standard clocking scheme where the periodic clock signal is deployed.