The Frequency Modulated Atomic Force Microscope (FM-AFM) is a powerful tool to perform surface investigation with true atomic resolution. The control system of the FM-AFM must keep constant both the frequency and amplitude of oscillation of the microcantilever during the scanning process of the sample. However, tip and sample interaction forces cause modulations in the microcantilever motion. A...

This paper proposes an improved sensorless control to estimate the rotor position of an interior permanent magnet synchronous motor. A phase-locked loop (PLL) is used to obtain the phase angle of the grid. The rotor position can be estimated using a PLL based on extended electromotive force (EEMF) because the EEMF contains information about the rotor position. The proposed method can reduce the...

This paper describes an oversampling data recovery circuit composed of an analog delay locked loop and a digital decision logic. The novel oversampling technique is based on the delay locked loop circuit locked to multiple clock periods rather than a single clock period, which generates the timing resolution less than the gate delay of the delay chain. The digital logic for data recovery was im...

In this paper, the modern nonlinear theory is applied to a third order phase locked loop (PLL) with feedback time delay. Due delay, different behaviors that are not accounted for in conventional PLL model identified, namely, oscillatory instability, periodic doubling and chaos. Firstly, Pade approximation used delay where it utilized deriving state space representation of under investigation. T...

Wireless communication is a fast-growing industry and recent developments focus on improving certain aspects of the area reducing power consumption while maintaining frequency operation. Phase Locked Loop (PLL) an integral part circuits which operate at very high frequencies. Frequency Detector (PFD) first block PLL key in determining computational capacity PLL. The PFD has to be reduced minimi...

Low inertia levels are typical in island power systems due to the relatively small rotational generation. Displacing generation units with static inertia-less PV results a significant increase frequency volatility. Virtual provided by inverter-storage can resolve this issue. However, low short circuit ratio (SCR) at point of common coupling together fast phase locked loop (PLL) will compromise ...

Figure 12: a) High-level block diagram of the segmented quantizer; b) quantization block details; c) signal processing model .. Figure 16: Estimated power spectra of a) the quantization noise sequences, and b) the running sums of the quantization noise sequences of the first-order ∆Σ modulator and the segmented quantizer presented in Section IV before and Ian Galton supervised the research whic...

issue of the stimulation of charge-pump phase-locked loops for built-in self-test applications. It is shown that three nodes of the PLL qualify for test signal injection. The hardware and methodology for each are discussed. In particular, a comprehensive explanation of the use of delta-sigma modulation in the time domain is provided. Furthermore, implementation issues of analog tests with signa...

Frequency-adaptive prefilters are widely used in the phase-locked loop (PLL) to suppress input disturbances. However, parameters of PLL and often designed separately or based on an inaccurate model. The positive feedback effect introduced by frequency adaption (FA) is usually ignored, leading non-optimal performance. Based accurate small-signal model with a particular focus FA, this paper propo...

High-voltage flexible power systems, with their intrinsic characteristics, play an increasingly important role in electronic systems. Synchronization between the inverter and grid needs to be achieved by a phase-locked loop (PLL), performance of which determines quality transmission. This paper proposes PLL adapted extremely harsh conditions. Firstly, traditional synchronous reference frame dua...