Phase-locked loop clock generator for a 1 GHz microprocessor

The design of a fully-integrated phase-locked loop (PLL) clock generator for a 1.0 GHz microprocessor using a 1.8 V 0.25 μm digital CMOS6X process is described. Hardware measurements are included, showing low jitter (<±36 psec active processor, <±9 psec quiet), high maximum lock frequency (1560 MHz), and wide lock range (1.9:1).