A subsampling stochastic coarse-fine ADC with SNR 55.3dB and >5.8TS/s effective sample rate for an on-chip signal analyzer

This paper presents a subsampling two-step coarse-fine stochastic A/D converter for on-chip measurement of high speed signals. Using equivalent time sampling techniques, we achieve an effective sampling rate of over 230 GS/s measurements for a 23.0023 MHz sine wave, and over 5.8 TS/s for an on-chip 2921.0115 MHz 7-bit PRBS while using a clock rate of 23 MHz. Our ADC achieves an SNR of 55.3 dB and SNDR of 40.6 dB without calibration for the sine wave measurement. We improve on previous work by reducing the number of comparators required per stochastic group while extending dynamic range to cover a rail-to-rail input signal.