EXOR gate and the J-K flip flop in that, its output is a function of both the frequency difference and phase difference between the two inputs. Figure 4 shows one implementation of a PFD. It basically consists of two D-type flip flops, with one Q output enabling a positive current source and the other Q output enabling a negative current source.

锁相环由三个模块组成：VCO压控振荡器，PD鉴相器，LF环路滤波器。 鉴相器也称 相位 比较器，PD顾名思义，就是对输出信号和参考信号之间的相位进行比较，其输出信号正比于两者的相位误差。 图1 PLL的模块功能. 其中u1是输入信号，w1是输入信号的角频率，ud是鉴相器输出信号，uf是LF滤波器的输出信号，u2是压控振荡器的输出信号，其中相位差定义为u1和u2之间的相位差。 PLL的工作原理是：若输入信号u1和u2的相位不相同，其相位差经过鉴相器输出为ud，经 …

2018年8月6日 · Conclusion: The noise suppression of the DPLL is about the same for all phase detectors as long as none of the edges of the reference get lost by fading. If fading occurs, the EXOR offers better noise performance. ) Specify f1(min), f1(max), f2(min), and f2(max). ) Design N unless otherwise specified.

2.3.2 Exor Phase Detector An exor type phase detector uses a digital exor phase comparator followed by a lowpass filter to extract the phase information at its inputs as shown in Figure 2.10.

Both the EXOR and the JK flip-flop have a severely limited pull-in range if the loop filter does not have a pole at zero. The PFD can detect both the phase and frequency difference between v1 and v2’. Conceptual diagram: The output signal of the PFD depends on the phase error in the locked state and on the frequency error in the unlocked state.

What is an All Digital PLL? An ADPLL is a PLL implemented only by digital blocks. The signal are digital (binary) and may be a single digital signal or a combination of parallel digital signals. No off-chip components. Insensitive to technology. All of the phase detectors so far had only a 1-bit or analog output. of v1 and v2’.

2016年2月5日 · An all-digital phase locked loop (ADPLL) was implemented in 180 nm CMOS technology. The proposed ADPLL uses a digitally controlled oscillator to achieve 3 ps resolution. The pure digital phase...

2022年10月10日 · Description of EXOR based PD, and its linear range and gain, analysis of EXOR PD for clocks with duty cycle error

In this paper we have designed and implemented two all-digital phase-locked loop models one with an XOR gate as phase detector and the other with edge triggered JK flip flop as Phase Detector. The proposed models are implemented by using Very High Speed Integrated Circuit Hardware Description Language.

2020年2月24日 · An all-digital phase locked loop (ADPLL) was implemented in 180 nm CMOS technology. The proposed ADPLL uses a digitally controlled oscillator to achieve 3 ps resolution. The pure digital phase locked loop is attractive because it is less sensitive to noise and operating conditions than its analog counterpart.