A Wide-Range 130-nm CMOS Statistic-Based Frequency Ratio Calculator

This paper presents the first frequency ratio calculator (FRC), which calculates the frequency ratio of an input signal and a reference signal with an accuracy better than 0.01. The circuit implementation is based on the proposed statistic algorithm such that its performance is resistant to PVT variation. Developed in 130-nm CMOS technology, the input signal frequency range of the FRC is from 135 to 850 MHz. The ratio calculation time takes only two reference cycles. The FRC consumes 4.3–15.9 mW from a 1.2V supply voltage for different input frequency.