....... 1.1 GHz Phase Locked Loop .......
Monolithic Engineering designed this world class PLL (Phase Locked Loop) for a two million transistor RISC(Reduced Instruction Set Computer) processor. This client is an industry leading, billion dollar "Blue Chip," American computer company who continues an unyielding commitment to high technology and successful vertical integration. This analog second order PLL contained a VCO(Voltage Controlled Oscillator) running between 650MHz and 1.1GHz, and was designed on a 0.13um CMOS(Complimentary Metal Oxide Semiconductor) process. Although the process was optimized for digital design, this PLL was designed using analog techniques. Highlights included a monolithic loop filter with adaptive feed forward control to maintain phase margin. Another feature was a duty cycle equalizer which maintained the VCO output duty cycle to within 48 to 52%. This second order duty cycle control loop contained its own charge pump to correct for temperature and process variations. Tools used were Mentor based platform running a Sun Solaris operating system on Sun Ultra Sparc 60 work stations. The original Mentor platform was augmented with proprietary schematic capture, simulation, parasitic extraction, and back annotation tools. Quality was established and maintained via ISO-9001 standards.