High-Speed, Low-Power, and Highly Reliable Frequency Multiplier for DLL-Based Clock Generator

Abstract

A high-speed, low-power, and highly reliable frequency multiplier is proposed for a delay-locked loop-based clock generator to generate a multiplied clock with a high frequency and wide frequency range. The proposed edge combiner achieves a high-speed and highly reliable operation using a hierarchical structure and an overlap canceller. In addition, by applying the logical effort to the pulse generator and multiplication-ratio control logic design, the proposed frequency multiplier minimizes the delay difference between positive- and negative-edge generation paths, which causes a deterministic jitter. Finally, a numerical analysis is performed to analyze and compare the performance of the proposed frequency multiplier with that of previous frequency multipliers. The proposed frequency multiplier is fabricated using a 0.13- $\mu \text{m}$ CMOS process technology, and has the multiplication ratios of 1, 2, 4, 8, and 16, and an output range of 100 MHz–3.3 GHz. The frequency multiplier achieves a power consumption to a frequency ratio of 2.9 $\mu \text{W}$ /MHz.