A 480 μW 2 GHz ultra low power dual-modulus prescaler in 0.25 μm standard CMOS

A dual modulus 128/129 prescaler is presented, consuming 480 μW at a power supply voltage of 1.8 V and an input frequency of 2 GHz or 98 μW at a power supply voltage of 1.5 V and an input frequency of 1 GHz. The prescaler was realized in Infineon 0.25 μm standard CMOS process using single-phase clocked flipflops in the phase-switching prescaler architecture. The circuit was optimized for minimal power drain, maintaining a maximum operating frequency of at least 2 GHz. Measured maximal frequency of operation of the prescaler was 2.5 GHz. A co-integration of the prescaler with a voltage controlled LC-oscillator showed no detoriation of the -110 dBc/Hz phase-noise performance of the VCO at 100 kHz frequency offset, thus proving the practical use of the circuit for synthesizers