A fractional-N LC-PLL in 28 nm CMOS that uses vertical layout integration techniques to achieve area reduction without performance penalties is proposed. The design utilizes multi-metal layers to vertically integrate dual interposed inductors on top of the active PLL circuit elements, resulting in an area of 0.07 mm 2 . The PLL covers a wide-frequency range from 2.7 GHz to 7 GHz, consuming a total power of 14 mW. At 7 GHz, the RMS jitter is 0.56 ps in integer mode and 1.1 ps in fractional mode.Index Terms-active loop filter, capacitor multiplier, fractional-N synthesizers, LC-PLL, patterned ground shield, spiral inductor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.