A modified midtread frequency quantization scheme for digital phase-locked loops

Abstract

A novel modified midtread quantizer is proposed for number-controlled oscillator frequency quantization in digital phase-locked loops (DPLLs). We show that DPLLs employing the proposed quantizer provide significantly improved cycle slip performance compared to those employing conventional midtread or midrise quantizers, especially when the number of quantization bits is small and the magnitude of input signal frequency normalized by the quantization interval is less than 0.5.