鎖相環 Phase-Locked Loop 一個鎖相環(PLL)是一個設計用於同步板子時脈與外部的時脈訊號的電路。鎖相環電路會比較外部訊號與電壓控制的石英震盪器(VCXO)之間的相位,接著會去修正震盪器的時脈訊號去與參考訊號的相位之間吻合。因此,訊號之間將會精密的同相。 當在處理訊號擷取時,由於鎖相環會使得多個裝置共享一...
What is Phase Lock Loop (PLL)? How Phase Lock Loop Works ? PLL Explained Topics covered in this article: Ⅰ. What is PLL(Phase Locked Loop)? Ⅱ. What’s the Structure of PLL? Ⅲ. How many types of PLL? Ⅳ. How does PLL Work? Ⅴ. Where to Use PLL? Ⅵ. What are the Character...
Phase lock loop–based algorithms for DSTATCOM to mitigate load created power quality problemsDSTATCOMharmonicsPFCphase detectorTHDZCDThis paper describes about implementation of phase﹍ocked loop (PLL)–based control algorithms for distribution static compensator (DSTATCOM) used to mitigate power quality...
Figure 8.(a) Bode magnitude and (b) phase plots of a crystal resonator measured by the frequency response analyzer of a Zurich Instruments lock-in amplifier. Figure 9.Schematic diagram showing the closed-loop control of a resonator by means of a PLL. The resonator together with the instrument...
Once the track signal on line 54 is produced, the phase-locked loop is closed so as to produce an output on line 48 at the input of the summing circuit 49 as explained with regards to FIG. 5 and to cause the lock detect circuit 72 to produce a lock signal on line 55 (also shown...
3.15.1 LOCK ACQUISITION Let us consider the PLL shown in Figure 3.61, where ωin = ωrf + Δω and ωout = ωfr. The term ωfr is the free running frequency of the VCO, and Δω is a relatively large input frequency step. The loop is initially locked at ωout = ωfr, and the...
The incoming frequency is doubled by the times-two multiplier, x2, and then used to lock LO2. The output of LO2 is divided by 2 and supplied as the second input to M2. Basic Math of BPSK One might be tempted to look at the waveform of Figure 4.3 and conclude that BPSK is a ...
VTUNE needs to be “precharged” to steer the VCO frequency close enough to the reference so that lock can be captured. In Figure 19, the measured phase noise results were impressive using the HMC1166 with analog PLL and AD829 op amp active loop filter. Using the same HMC1166 VCO, we...
of 0. As long as the phase shift θeis within the locking range ΔwL, the phase detector12will track and lock the phase shift θeto have a value of 0. Notice that just because the output uddhas a value of 0, it does not necessarily imply that the phase shift θehas a value of ...
The feedback loop of the output signal CKout to CKfb causes the phase of the output signal CKfb to “lock” on the phase of the input signal CKin. As indicated above, the frequency dividers 14 and 22 are configured to adjust the frequency of the output signals CKout and CKfb by a...