A divider-less sub-harmonically injection-locked PLL with self-adjusted injection timing

Abstract

A low-phase-noise phase-locked loop (PLL) is widely used in clock generation, frequency synthesis, and data conversion. In a PLL using a sub-sampling phase detector (SSPD) achieves not only low phase noise, but also low power. In a low-phase-noise sub-harmonically injection-locked PLL (SIPLL) is presented. The injection timing of a SIPLL is sensitive to the process, voltage, and temperature (PVT) variations. In addition, the divider of a SIPLL [3-5] cannot be powered down to save the power as in [1, 2]. In this paper, a divider-less SIPLL with self-adjusted injection timing is presented.