A 1.5-V 250-MHZ TO 3.0-V 622-MHZ OPERATION CMOS PHASE-LOCKED LOOP WITH PRECHARGE TYPE PHASE-FREQUENCY DETECTOR

A new approach which implements a simple, high-speed phase detector wi th precharge logic will be presented. The minimum detectable phase dif ference is 40 psec, which is less than a half of conventional detector s. A current mode ring oscillator with a complementary-input bias gene rator has also been developed to enhance the dynamic range of the VCO under a low supply voltage, A fully CMOS PLL was designed using 0.5-mu m technology. By virtue of this simple, fast detector, the wide opera tion range of 250 MHz at 1.5 V to 622 MHz at 3.0 V was achieved by sim ulation.