A 14mW Fractional-N PLL Modulator with an Enhanced Digital Phase Detector and Frequency Switching Scheme

摘要

A 2.2GHz fractional-N synthesizer with a digital phase detector and a dual switching scheme is presented. An additional feedback loop incorporating phase oversampling helps to achieve a measured noise performance of -133dBc (-106dBc) at a 10MHz (1 MHz) offset. The MSK modulation rate is 927.5kb/s. The 0.7mm² prototype IC, implemented in a 0.13mum CMOS process, consumes 14mW from a 1.4V supply.