An Extended Range Divider Technique for Multi-Band PLL

This paper presents a multiplexer-based extended range multi-modulus divider (ER-MMD) technique for multi-band phase locked loop (PLL). The architecture maintains a modular structure by using conventional 2/3 divider cells and a multiplexer without adding any extra logic circuitry. The area and power overhead is minimal. The 2/3 divider cells are designed using true single phase clock (TSPC) logic for ER-MMD to operate in the sub-10 GHz range. A division range of 2 to 511 is achieved using this logic. The ER-MMD operates at a maximum frequency of 6 GHz with a worst-case current of 625 μA when powered with a 1 V supply. A dual voltage controlled oscillator (VCO), L5/S band PLL for Indian Regional Navigation Satellite System (IRNSS) application is designed, which incorporates an ER-MMD based on the proposed approach as a proof of concept. This technique achieves the best power efficiency of 12 GHz/mW, among the state-of-the-art ER-MMD designs.