On-chip jitter and oscilloscope circuits using an asynchronous sample clock

We demonstrate digital circuits for measuring the jitter histograms of gigahertz clock and data signals. The circuits do not require calibration, and an asynchronous sampling technique alleviates the need for an on-chip sample clock generator with delay control. We combine measurements across swept reference voltages to create statistical clock signal and eye diagram waveforms at 6GHz and 5Gbit/s, respectively. The proposed technique produced RMS jitter measurements of 2.0ps on clock signals and 6.2ps on random data signals.