12 bit 3.072 GS/s 32-way time-interleaved pipelined ADC with digital background calibration for wideband fully digital receiver application in 65 nm complementary metal–oxide–semiconductor

摘要

The performance of a wideband receiver is highly dependent on the performance of the analogue-to-digital converter (ADC) used. Such applications require ADCs to operate at ultra-high speeds with high accuracy for inputs ranging from 40 MHz - 1 GHz. Conventional solutions either use filters and mixers to extract the frequency of interest and convert it using a low-speed ADC or use a single ultra-high-speed flash converter. Both of these solutions consume ultra-high power and require complex circuitry, which expands exponentially with the converter resolution. In this work, a 12 bit 3.072 GS/s time-interleaved pipeline ADC is proposed. In total, 32 pipeline ADCs, each with a sampling rate of 96 MS/s, are interleaved in the time domain to achieve an overall sampling rate of 3.072 GS/s. In addition to the potential energy-saving capabilities of a time-interleaving structure, the circuit adopts amplifier sharing in sample-and-hold circuits, further improving the power efficiency. To account for interleaving mismatch, the circuit uses a pure background calibration technique, maintaining the system linearity and spectral efficiency. The proposed design achieves signal-to-noise-and-distortion ratio of 53.65 dB and spurious-free dynamic range (SFDR) of 69.04 dB while consuming 820 mW of power at a 1.2 V supply, resulting in a figure-of-merit of 0.67 pJ/conv-step.