A 1GS/s 82dB Peak-SFDR 12b Single-Channel Pipe-SAR ADC with Harmonic-Injecting Cross-Coupled-Pair and Fast N-replica Bootstrap Switch Achieving 7.5fj/conv-step

摘要

High-speed medium-resolution ($geq$ 10bits) ADCs enable direct RF sampling transceivers, which eliminate mixers and hence the troublesome mixing spurs. However, one major limitation of direct RF sampling is its limited SFDR/SNDR at RF frequencies mainly due to the challenge in designing a single-channel ADC with high speed and high linearity. This paper presents a 1GHz-ERBW 1GS/s 12b single-channel Pipe-SAR ADC with an peak SFDR 82dB and SNDR of 60.7dB at Nyquist input. As shown in Fig.1. The proposed three-stage Pipe-SAR ADC operates in a fully asynchronous fashion. The bits of the capacitor array in each of the three stages, CDAC1-CDAC3, are 4b, 4b and 6b, with size of 700fF, 40fF and 50fF, respectively. The residue amplifiers (RA), RA1 and RA2, both have a gain of about 8.