A Fast Switching Full-CMOS PHS Frequency Synthesizer with an Auxiliary Coarse Tuning Method

This paper presents a fast switching CMOS frequency synthesizer with a new coarse tuning method for PHS applications. To achieve the fast lock-time and the low phase noise performance, an efficient bandwidth control scheme is proposed. Charge pump up/down current mismatches are compensated with the current mismatch compensation block. Also, the proposed coarse tuning method selects the optimal tuning capacitances of the LC-VCO to optimize the phase noise and the lock-time. The measured lock-time is about 20μs and the phase noise is -121dBc/√Hz at 600kHz offset. This chip is fabricated with 0.25μm CMOS technology, and the die area is 0.7mm × 2.1mm. The power consumption is 54mW at 2.7V supply voltage.