Extension method of tolerance to voltage and temperature variations in an injection-locked PLL

Abstract

This article presents a method to enhance tolerance to voltage and temperature variations in an injection-locked PLL. The proposed method can enhance the tolerance to voltage and temperature variations by turning on or off a supplementary current source of the oscillator in the injection-locked PLL through the RC switch with a large time constant. This configuration increases the tolerance range to the supply voltage variation by 33.8%, compared to the conventional injection-locked PLL in [5]. The proposed method is verified by the calculation and simulations. They show that the PLL can maintain the stable lock state during the switching of the supplementary current source.