New implementation of phase-switching technique and its applications to GHz dual-modulus prescalers

A new implementation of the phase-switching technique is proposed in which the phase selection and phase control are implemented in simple logic circuits. A divide-by-128/129 dual-modulus prescaler using the proposed phase-switching technique is presented to evaluate the new implementation potentialities. The prescaler is implemented in 0.25 μm standard CMOS process. The measured results show that this prescaler works well in the gigahertz frequency range. It draws 4.7 mA current from the 2.5 V power supply (while three power-hungry output buffers consume 8.8 mA current) when the input frequency is 2.3 GHz. The die area is only 0.47×0.47 mm²