A linear phase detector for arbitrary clock signals

A new phase detector is proposed and analyzed. Its linear differential structure leads to significant advantages such as the absence of a dead zone, an insensitivity to common mode noise on input signals, a low switching activity that reduces noise and power dissipation, and finally, a good acquisition behaviour. The proposed detector can detect phase differences between various signals selected from a broad class of clock signal waveform types. Moreover it has a very low phase offset, in spite of process variations. Results presented in this paper show that the proposed detector can cover a wide range of frequencies that reaches up to 2 GHz when implemented with TSMC 0.35 micron CMOS. The detector remains accurate up to the highest experimental frequencies. Its simple topology uses only 26 MOS transistors, most of which can be of minimum size.