Design of a 1-V 3-mW 2.4-GHz fractional-N PLL synthesizer in 65nm CMOS

A fractional-N PLL synthesizer is designed in 65 nm CMOS general process for Bluetooth low-energy applications. For low-power consumption, the PLL synthesizer is designed in a single 1-V supply. The tuning range of PLL Synthesizer is 1.9–2.7 GHz to cover the ISM band for 1/5-fRF sliding-IF receiver. The simulated VCO phase noises at 1 MHz offset are −110 and −120 dBc/Hz at 2.7 and 1.9 GHz, respectively. With a fast VCO frequency calibration process included, the total lock time of the synthesizer is 12 μs. The synthesizer dissipates 3 mW from 1 V supply voltage.