A 1.26mW/Gbps 8 locking cycles versatile all-digital CDR with TDC combined DLL

Abstract

This paper presents an all-digital CDR with TDC combined DLL which can be used for not only NRZ signaling but also pulse-based communication. The TDC combined DLL can realize a small area, low power and fast locking by sharing the delay line of the TDC with the DLL. The proposed CDR can recover the clock by evaluating a waveform of one cycle, and detect edge from a pulse-based signal. Locking time is within 8 clock cycles, and power efficiency is 1.26mW/GHz at 1Gbps and 0.7V power supply. The rms and peak-to-peak jitter at 2.3Gbps and 1.0V are 5.44ps and 37.4ps, respectively. Die area is 0.0297mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .