A fast-settling PLL frequency synthesizer with direct frequency presetting

Abstract

A PLL frequency synthesizer with frequency presetting is implemented in a 0.35mum CMOS process and occupies 0.4mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The output frequency is between 560 and 820MHz, the supply is 3.3V, the measured settling time is <10 μs and the phase noise is -85dBe/Hz at 10kHz offset. The synthesizer can automatically compensate for frequency variation with temperature