A low-jitter and low-phase noise switched-loop filter PLL using fast phase-error correction and dual-edge phase comparison technique

Abstract

This paper presents a low-jitter and low-phase noise type-II charge pump and switched-loop filter-based (SLF) phase-locked loop (PLL) with a fast phase error correction technique (FPEC) and a newly proposed dual-edge phase comparator (DEPC). To improve the phase noise, the bandwidth of the proposed PLL is extended to fREF/5 using the proposed DEPC. It consists of four D flip-flops in true single-phase clock (TSPC) logic, four current-mode logic-based inverters, and two logic OR gates. Unlike conventional DEPCs, the proposed DEPC has a small reset pulse width duration and negligible blind zone, and due to this, it can perform at higher frequencies along with an increased phase detection range. The proposed architecture is implemented for a 2.4 GHz output frequency that embodies DEPC and SLF using the FPEC technique in an 180-nm Semi-Conductor Laboratory (SCL) CMOS process. The proposed DEPC can work up to a maximum of 3.45 GHz frequency with 145 ps of reset delay. The proposed PLL accomplishes the 40 MHz bandwidth with a 200 MHz reference clock. The simulated rms jitter integrated from 10 kHz to 100 MHz and the phase noise of the output signal at an offset of 1 MHz are 860 fs and −122 dBc/Hz respectively. The proposed architecture occupies an area of 0.032 mm2 and consumes 8.2 mW from 1.8 V power supply.