Enabling Fine Sample Rate Settings in DSOs with Time-Interleaved ADCs

The time-base used by digital storage oscilloscopes allows limited selections of the sample rate, namely constrained to a few integer submultiples of the maximum sample rate. This limitation offers the advantage of simplifying the data transfer from the analog-to-digital converter to the acquisition memory, and of assuring stability performances, expressed in terms of absolute jitter, that are independent of the chosen sample rate. On the counterpart, it prevents an optimal usage of the memory resources of the oscilloscope and compels to post processing operations in several applications. A time-base that allows selecting the sample rate with very fine frequency resolution, in particular as a rational submultiple of the maximum rate, is proposed. The proposal addresses the oscilloscopes with time-interleaved converters, that require a dedicated and multifaceted approach with respect to architectures where a single monolithic converter is in charge of signal digitization. The proposed time-base allows selecting with fine frequency resolution sample rate values up to 200 GHz and beyond, still assuring jitter performances independent of the sample rate selection

A 161-mW 56-Gb/s ADC-Based Discrete Multitone Wireline Receiver Data-Path in 14-nm FinFET

This article introduces a wireline receiver (RX) data-path employing discrete multi-tone (DMT) modulation for communicating over electrical links. The DMT RX incorporates a fully digital equalization data-path, with a synthesized and automatically placed and routed digital signal processor (DSP) following a 10-bit time-interleaved pipelined successive-approximation register analog-to-digital converter (TI-PISAR ADC). The prototype RX chip implemented in a 14-nm FinFET process demonstrates a lane data rate of 56 Gb/s dissipating 161 mW including the ADC and the DSP power. The energy efficiency of 1.2 pJ/b for the DSP and 2.9 pJ/b for the entire RX was achieved with the data-rate of 56 Gb/s for communicating over channels exhibiting up to 28-dB loss at 14 GHz with a bit-error-rate (BER) better than 2e-4