A Fractional-N PLL for Digital Clock Generation With an FIR-Embedded Frequency Divider

−In this paper, a novel architecture of a fractional-N phase-locked loop (PLL) is presented for digital clock generation. By employing multimodulus dividers in parallel with sequential outputs of a ∆Σ modulator, finite impulse response (FIR) filtering with respect to modulator noise is realized in the PLL, resulting in quantization noise reduction in high frequencies. Hence, a low oversampling ratio (OSR) ∆Σ fractional-N PLL can be achieved without increasing quantization noise. Architecture comparison and simulation results are also presented.

• Type: Conference
• Year: 2007
• Where: ISCAS
• Authors: Baoyong Chi, Xueyi Yu, Woogeun Rhee, Zhihua Wang
• Keywords: Fractional-N Phase-locked Loop, ISCAS 2007, Quantization Noise, Quantization Noise Reduction