A fully integrated CMOS frequency synthesizer for Bluetooth

A low power, fully integrated 2.4 GHz fractional-N frequency synthesizer for Bluetooth in a 0.25 /spl mu/m CMOS technology is presented. The complete synthesizer, including a fully integrated VCO, consumes 22 mA from a 2.5 V supply. The integrated VCO reaches a phase noise of -133 dBc/Hz at 3 MHz. The synthesizer is designed for a direct /spl Sigma//spl Delta/-modulation of the PLL.