A scalable synchronous reload technique for wide division range multi modulus dividers

This work presents a detailed study for the logic of multi modulus frequency dividers (MMDs) with multiple modulus extensions. These MMDs have higher power efficiency compared to conventional pulse swallow dividers. In integer-N phase locked loops (PLLs), these MMDs are fully functional over their entire division range. In fractional-N PLLs however, certain division ratios cause the PLL to lose lock which makes multi-standard designs more challenging. In this work, a generic scheme that mitigates this issue is proposed which according to the best of the authors' knowledge leads to the simplest truly-continuous wide-division-range MMD for fractional-N PLLs.