A 200 MHz frequency-locked loop based on new frequency-to-voltage converters approach

In this paper, we propose a high frequency, fully integrated frequency-locked loop (FLL) design based on a new architecture of a CMOS frequency-to-voltage converter. The design is similar to a phase-locked loop (PLL) in the way that it generates an output signal that tracks an input reference signal, however, in this case the two signals are synchronized in frequency and not in phase. The frequency of the FLL output could be also controlled by an input voltage, therefore, it could be also used as an integrated high-precision voltage-controlled oscillator. The proposed FLL is very fast, operates over a wide frequency range and occupies a small integrated area compared to an equivalent PLL