That is to say, they all contain multiple current switches that are controlled to add charge to or remove charge from a downstream circuit, which as a consequence generates an appropriate output voltage to control the VCO 16 and to move {TAIL ~ the PLL} toward {HEAD ~ a phase locked state} 
That is to say , they all contain multiple current switches that are controlled to add charge to or remove charge from a downstream circuit , which as a consequence generates an appropriate output voltage to control the VCO 16 and to move { TAIL ~ the PLL } toward { HEAD ~ a phase locked state }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD