A dynamic current mode design approach of 2/3 prescaler for phase locked loop application

Abstract

Though Current Mode Logic has excellent features like higher switching speed and reduced crosstalk due to small output swing, there exists numerous flaws such as static power dissipation, non-suitable for power-down modes and comparably higher design complexity of load resistors. To address the aforementioned worries, this article incorporates a dynamic current mode design approach having active load and controlled current source to configure an improved (2/3) dual modulus prescaler. Simulation results of the proposed circuit using Cadence Virtuoso platform for 90 nm CMOS at 1.2 V supply depict a power consumption of 2.517 mW when driven by a high frequency of 2 GHz. The phase noise and output noise are found to be -147.001 dBc/Hz and -181.7 dB at 1 MHz offset while it reads a self-oscillation frequency of 5 GHz. The variation tolerance of the design is proved via 5% skew-based simulation at all corners; whereas the correct functionality at 28 nm UMC justifies its scalability.