In previous work, we have shown that second-order phase locked loop (PLL) with sinusoidal phase detector characteristics have a separatrix cycle for a certain value of closed loop gain. It was verified that bifurcation from a stable separatrix cycle is the mechanism responsible for breaking the limit cycle associated with the PLL’s out-of lock state and the loop pulls in (phase lock). The value...

Novel frequency doubler circuits and dividers for clock signal generation are presented. In combination with two edge detectors and two duty cycle control buffers a low cost frequency doubler circuit is achieved as compared to Phase-Locked Loop (PLL) design. An input clock signal with an unpredictable duty cycle is inputted to a rising (or falling) edge detector. The edge detector converts the ...

A 3.2Gb/s clock and data recovery (CDR) circuit for a high-speed serial link without the reference clock is described. The CDR has a phase and frequency detector (PD and FD), which incorporates a half-rate bang-bang type oversampling PD and a half-rate frequency detector that can achieve low-jitter operation and improve pull-in range. The PD of oversamping method finds a phase error by generati...

We have developed a wideband digital frequency detector for high-speed frequency modulation atomic force microscopy (FM-AFM). We used a subtraction-based phase comparator (PC) in a phase-locked loop circuit instead of a commonly used multiplication-based PC, which has enhanced the detection bandwidth to 100 kHz. The quantitative analysis of the noise performance revealed that the internal noise...

Design and simulation of Digital PLL has been illustrated in this paper. The Digital PLL is given signal of 400 MHz to 900 MHz in the UNII (Unlicensed National Information Infrastructure) lower band which is used by IEEE 802.11(a). All the Digital PLL blocks are designed and simulated using Simulink. It is verified that Digital PLL is stable with a phase margin of 91.1 degree which satisfy the ...

--The All-Digital Phase-Locked Loop (ADPLL) is digital electronic circuit that are used in modern electronic communication systems like frequency synthesizer, modulator/demodulator etc. This paper presents a review of various ADPLL techniques. The range of input frequency of ADPLL is 40 to 98 MHz; the output frequency may be up to 2.92 to 4 GHz range. The components of ADPLL such as phase detec...

In a classical PLL, the phase detector (PD) and charge pump (CP) noise is multiplied by N, when referred to the VCO output, due to the divide-by-N in the feedback path. It often dominates the in-band phase noise and limits the achievable PLL jitter·power Figure-Of-Merit (FOM). A subsampling PLL uses a PD that sub-samples the high frequency VCO output with the reference clock. The PD and CP nois...

Referring to Figure 1, a system for using a PLL to generate higher frequencies than the input, the VCO oscillates at an angular frequency of ωO. A portion of this signal is fed back to the error detector, via a frequency divider with a ratio 1/N. This divided down frequency is fed to one input of the error detector. The other input in this example is a fixed reference signal. The error detector...

In this letter, we propose a polarity decision carrier recovery algorithm that is useful for carrier acquisition in high order QAM. The PD (Phase Detector) output and its variance characteristic are mathematically derived and the simulation results are presented. The proposed algorithm shows enhanced acquisition performance especially for large frequency offset. key words: carrier recovery, QAM...