A 0.65-V 2.5-GHz Fractional-N Synthesizer With Two-Point 2-Mb/s GFSK Data Modulation

作者：Yu Shih An^*; Kinget Peter

来源：IEEE Journal of Solid-State Circuits, 2009, 44(9): 2411-2425.

DOI：10.1109/JSSC.2009.2023156

• Fractional-N
• frequency synthesis
• GFSK
• ISM
• modulator
• RF
• ultra-low voltage
• voltage-controlled oscillator

We present ultra-low-voltage circuit design techniques for a fractional-N RF synthesizer with two-point modulation which was realized in 90-nm CMOS using only regular V(T) devices.; the voltage controlled oscillator, phase-frequency detector and charge pump operate from a 0.5 V supply while the divider uses a 0.65 V supply. The frequency synthesizer achieves a phase noise better than 120 dBc/Hz at 3 MHz, while consuming 6 mW. A calibration technique to equalize the gain between the two modulation ports is introduced and enables phase/frequency modulation beyond the loop bandwidth of the phase-locked loop. Measurement results for 2-Mb/s GFSK modulation are presented.

• 出版日期2009-9