A Wide-Range Frequency Synthesizer Using a Compensated Phase-Rotating Technique for Digital TV Tuners

摘要

Fabricated in a 0.18μCMOS technology, a wide-range fractional-N frequency synthesizer with a phase-compensated technique is presented. While using a 630-960 MHz LC-type VCO, the synthesizer can provide the range of 55 to 960 MHz with a band-selecting structure to satisfy the ATSC applications. Using the phase-rotating concept, the synthesizer can achieve the fractional functionality, instead of the conventional ΔΣ interpolation. The measured results show phase noise is -123 dBc/Hz at 1-MHz offset. The lock time is below 6μs from 640 MHz to 930 MHz.