A time-to-digital converter using multi-phase-sampling and time amplifier for all digital phase-locked loop

This work presents a high timing resolution and wide measured timing range time-to-digital converter (TDC) for all digital phase-locked loop (ADPLL). The multi-phase outputs of digital controlled oscillator (DCO) utilize to sample the timing difference and extend its detectable timing range. A time amplifier (TA) is further applied to enhance the timing resolution. This design requires less silicon area compared to traditional TDCs. The TDC is realized by using a 90 nm CMOS process. TDC achieves a 6.8 ps timing resolution and a measured timing range from 12 ps to 9.5 ns. The DNL and INL are ±0.85 LSB and ±3.5 LSB, respectively. The power dissipation is 240 uW at 0.5 V supply voltage.