A Phase-to-Digital Converter for wide tuning range and PVT tolerant ADPLL operating down to 0.3 V

A Phase-to-Digital Converter (PDC), - an improved scheme of Time-to-Digital Converter (TDC) -, is presented. The resolution of PDC is completely tracking to generated clock period. This scheme effectively reduces the calibration efforts in conventional TDC. The key technologies are digitally Controlled Coupled Oscillator (DCCO) and body-bias controlled vernier TDC. This PDC should be a key component of wide tuning range and PVT variation tolerant All Digital PLL (ADPLL).